Kustomer to HubSpot Service Hub migration requires API extraction (CSV exports lose message bodies), KObject-to-Custom-Object mapping on Enterprise, and 2–4 weeks of careful ETL work.
Migrating from Kustomer to HubSpot Service Hub is a medium-to-high complexity project because there is no native migration path—HubSpot's Kustomer Data Sync app only syncs customer profiles, not tickets or conversation history. The fundamental challenge is a data model mismatch: Kustomer's customer-centric timeline architecture, where Conversations, Messages, Notes, and KObjects all hang off a single Customer record, does not map 1:1 to HubSpot's relational ticket-to-engagement model. Custom API extraction work is required for full message bodies (CSV exports only include previews), KObjects demand HubSpot Enterprise with Custom Objects, and all Business Rules, Workflows, Saved Searches, and Snippets must be manually rebuilt in HubSpot.
Read this first
Pair-specific gotchas that catch teams out. Each one has cost somebody a weekend.
TL;DR — Kustomer to HubSpot Service Hub Migration
A Kustomer to HubSpot Service Hub migration is a medium-to-high complexity data-model translation project. Kustomer's customer-centric timeline architecture — where Conversations, Messages, Notes, and KObjects all hang off a single Customer record — does not map 1:1 to HubSpot's relational ticket-to-engagement model. The realistic timeline is 2–4 weeks for under 100K conversations, 4–6 weeks for larger datasets with complex KObject schemas. The single biggest risk is losing full conversation transcript history: Kustomer CSV exports only include message previews, not full message bodies, so you must extract via the REST API. KObjects require HubSpot Enterprise (the only tier supporting Custom Objects), and Kustomer's Business Rules, Workflows, and Saved Searches cannot be exported — they must be rebuilt manually in HubSpot. HubSpot's native Kustomer Data Sync app syncs customers, not tickets, so it is not a migration tool. (ecosystem.hubspot.com) Teams with fewer than 10,000 conversations and no KObjects can self-serve with API scripts. Anything above that — especially with attachments, KObjects, and multi-threaded conversation history — benefits from a managed migration service.
The CRM Search API is your bottleneck, not the batch create endpoint
If you deduplicate contacts or tickets during import by searching HubSpot first, the 5 requests/second limit across all search endpoints becomes the primary constraint. Build your deduplication logic in your staging layer, not inside the HubSpot API call chain.
Knowledge Base migration deserves separate planning
For most teams, KB migration is a 2–5 day manual effort depending on article count. HubSpot's CSV import path supports up to 400 articles per import with no table import support. If your Kustomer KB has 200+ articles, budget the time explicitly. Kustomer can expose KB content through its API, which at least lets you automate the extraction side. (help.kustomer.com)
Preserve historical timestamps
When creating email engagements, set hs_timestamp to the original Kustomer message createdAt value (converted to Unix ms). Without this, all migrated conversations appear as if they happened on the import date, destroying timeline chronology. The same applies to tickets — pass the original creation date in the API payload, otherwise HubSpot stamps every historical ticket with today's date.
Change management tip
Brief your support team on HubSpot's Help Desk workspace 1–2 weeks before go-live. The interface shifts from Kustomer's timeline-first view to HubSpot's ticket-list-first view. Agents who relied on Kustomer's unified timeline will need time to adjust to navigating between ticket records and associated engagement histories. Budget 2–4 hours of hands-on training per agent, ideally using migrated sandbox data so they can practice with familiar conversations.
The runbook
Work top to bottom. Tick steps as you go — your progress is saved in this browser.
01 Discovery Establish why you are moving, what "done" means, and who signs off.
Objective A written scope with agreed success criteria, a named owner per workstream, and a budget approved by finance.
Keep these open
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Pull the real numbers out of Kustomer
Export counts for tickets (open and closed separately), contacts, organisations, attachments, macros, triggers, automations, views and SLA policies. Note the oldest ticket date — history depth drives the whole timeline. Estimating from memory is the single most common cause of a blown migration window.
Data Profiler Get real record counts instead of estimating from memory -
Decide what history actually moves
Agree a cut-off with the support lead: all history, last 24 months, or open tickets plus a read-only archive. Every extra year of closed tickets adds API time and cost without adding much agent value. Get this in writing — it is the decision people relitigate mid-cutover.
A "move everything" default is what turns a two-week migration into a two-month one.
COI & ROI Calculator Build the 36-month business case you will need for sign-off -
Confirm HubSpot Service Hub can hold your support model
Walk your current workflow through HubSpot Service Hub: multi-brand, business hours, SLA targets, CSAT, side conversations, public vs internal notes, and any channel you depend on (voice, chat, WhatsApp, social). List anything with no native equivalent — those are project risks, not configuration details.
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Build the business case
Model licence delta, migration effort, agent retraining, and the cost of staying put (Cost of Inaction). Executives approve a number, not a plan, and you will be asked for it again at the go/no-go.
Helpdesk Migration Planner Turn ticket volume into a dated Kustomer → HubSpot Service Hub timeline -
Name owners and set the go/no-go date
One named owner each for data, configuration, integrations, and agent enablement, plus a decision-maker who can call a rollback. Put the go/no-go meeting in calendars now, 48 hours before the freeze.
Kustomer → HubSpot Service Hub specifics
- Go-to-market unification
- When sales, marketing, and support all operate within HubSpot, teams eliminate data silos and reduce iPaaS licensing costs. Organizations running Kustomer alongside HubSpot CRM typically spend $5,000–$15,000/year on integration middleware (Zapier, Make, Workato) that becomes unnecessary after consolidation.
- Predictable pricing
- HubSpot's published tiered pricing (Service Hub Professional starts at $100/seat/month, Enterprise at $150/seat/month as of early 2025) replaces Kustomer's opaque, negotiated contracts. For a 20-agent team, HubSpot Service Hub Professional runs approximately $24,000/year versus Kustomer's typical $30,000–$60,000/year range depending on negotiated rates.
- Ecosystem breadth
- HubSpot's App Marketplace offers 1,700+ integrations compared to Kustomer's smaller third-party ecosystem.
- Kustomer's unified timeline
- In Kustomer, every event (messages, KObjects, notes, system events) appears on one chronological timeline per customer. HubSpot splits this across ticket timelines, contact activity, and separate engagement records.
Don't move on until
- Record counts confirmed for tickets, contacts, organisations and macros
- Success criteria signed off by the support lead
- Freeze window provisionally booked with the business
02 Data Audit Find out what is actually in the data before you try to move it.
Objective A profiled, cleaned export with every quality defect either fixed at source or explicitly accepted.
Keep these open
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Take a full Kustomer export and profile it
Export to CSV or JSON and profile every file: row counts, null rates per column, distinct values, and type consistency. Compare row counts against the API totals from Discovery — a gap here means your export is silently truncated, usually by pagination.
Data Profiler Profile the Kustomer export for nulls, outliers and type drift -
Validate file structure before anyone writes a transform
Check delimiters, quoting, encoding (expect UTF-8, watch for BOMs and Latin-1), duplicate headers, and embedded newlines in ticket bodies. Ticket descriptions with raw newlines and commas break naive CSV parsers and silently shift columns.
A single unescaped quote in one ticket body can shift every subsequent column without any error.
CSV Validator Catch broken headers and ragged rows in the raw export -
Inventory PII and set retention
Scan for emails, phone numbers, payment card fragments, national IDs and anything else regulated in ticket bodies and custom fields — support tickets are where customers paste things they should not. Decide what gets migrated, masked, or dropped, and record the legal basis.
Ticket bodies and attachments routinely contain card and ID data that never appears in a structured field.
PII & Compliance Scanner Find regulated fields before they land in a new system -
Quantify duplicates, orphans and dead references
Count duplicate contacts (same email, different casing), tickets whose requester no longer exists, organisations with no members, and attachments whose parent ticket is gone. Fix these in Kustomer where you can — migrating them just moves the mess.
Data Cleaner Strip empty rows, stray whitespace and dead columns -
Clean and normalise the export
Trim whitespace, drop empty rows and columns, normalise casing on emails and tags, and standardise every timestamp to UTC ISO 8601. Timezone drift is invisible at load time and shows up weeks later as SLA reports nobody can reconcile.
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Produce a masked copy for sandbox work
Generate a realistic but fake version of the export for testing and for any vendor who needs sample data. Loading real customer PII into a sandbox is a breach in most jurisdictions, and sandboxes are rarely covered by your DPA.
PII Masker Generate a safe copy for sandbox and vendor testing
Kustomer → HubSpot Service Hub specifics
- Kustomer Events / Audit Logs
- System-level events (assignment changes, status transitions) have no bulk export path and no direct HubSpot equivalent. Flatten these into note engagements or discard after review.
- Callable Workflows
- Kustomer's workflow automation that connects to external APIs must be redesigned using HubSpot Workflows with Custom Code actions or Operations Hub.
- Snippets and Shortcuts
- These have no export path from Kustomer. Rebuild as HubSpot Snippets manually.
- Permission model granularity
- Kustomer's role-based access control allows fine-grained permissions at the object and field level. HubSpot's permission model is coarser — roles control feature access (e.g., "edit contacts") rather than field-level visibility. If your Kustomer setup uses restricted field access for compliance (e.g., PII masking for certain agent roles), you'll need to evaluate HubSpot's field-level permissions (available on Enterprise) and potentially restructure your access control model.
Don't move on until
- Export parses cleanly with no ragged rows or encoding errors
- PII inventory complete and retention decisions recorded
- Duplicate and orphan records quantified and triaged
03 Field Mapping Turn two schemas into one signed-off mapping spec.
Objective A reviewed field-level mapping covering every object, with an explicit decision for every field that has no target.
Keep these open
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Generate the first-pass Kustomer → HubSpot Service Hub field map
Start from an automated match on both schemas, then review every row by hand. Automated matching gets the obvious 70% right and is confidently wrong on the rest — especially anything named "type", "status" or "custom_field_1".
Schema Mapper Opens pre-loaded with the Kustomer → HubSpot Service Hub field pair -
Map status, priority and channel values, not just field names
Enumerate every value in each picklist on both sides and map them explicitly. Value-level mismatches are the defect class that survives all the way to production because the field itself mapped fine — a ticket that should be "Pending" arriving as "Open" reopens SLA clocks.
Statuses with no target equivalent (on-hold, pending-customer) need a policy decision, not a best guess.
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Decide how custom fields land
Create the target custom fields first, matching type exactly (a dropdown mapped to free text can never be mapped back). Where HubSpot Service Hub has no equivalent, decide between a new custom field, a tag, or a note appended to the ticket body — and record which.
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Resolve identity and threading
Decide how source IDs are preserved — most platforms will not let you set the primary key, so keep the original ID in a custom field. Without it, reconciliation becomes fuzzy matching and every future support question about an old ticket is unanswerable.
Losing the original ticket ID makes reconciliation and rollback effectively impossible.
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Plan attachments, inline images and threading order
Confirm size limits, allowed MIME types, and whether inline images survive as attachments or need rehosting. Decide the comment ordering and author attribution rules: comments loaded out of order, or all attributed to the API user, destroy the conversation history agents rely on.
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Freeze and sign off the mapping spec
Version the spec, walk the support lead through it row by row, and get explicit sign-off. Any change after this point goes through change control — mid-flight mapping edits are how partial loads happen.
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Note body length
HubSpot note engagements are capped at 65,536 characters. Long Kustomer notes must be split into sequential notes with preserved timestamp ordering.
Kustomer → HubSpot Service Hub specifics
- Picklist / enum values
- Kustomer uses free-text or custom attribute enums. HubSpot requires internal values to be pre-defined in property settings before import. Export all Kustomer enum values, create matching HubSpot dropdown options first, then map on import. (knowledge.hubspot.com)
- Date fields
- Kustomer stores timestamps in ISO 8601 format. HubSpot's API accepts Unix timestamps in milliseconds for date properties. Every date field needs conversion.
- Multi-value fields
- Kustomer Customer emails and phones are JSON arrays. HubSpot Contacts have a single email property plus hs_additional_emails (semicolon-separated).
- Conversation status → Pipeline stage
- Kustomer statuses (open, snoozed, done) must map to HubSpot ticket pipeline stage IDs. Retrieve your pipeline stages first via GET /crm/v3/pipelines/tickets and build a lookup table.
- Multi-select tree fields
- Kustomer's multi-select tree fields must be flattened into HubSpot dropdown select properties.
Don't move on until
- Every source field is mapped, deliberately dropped, or parked in a custom field
- Status, priority and channel value maps agreed with the support lead
- Mapping spec version-controlled and signed off
04 Test Migration Prove the pipeline on a small, representative slice.
Objective A pilot load into a HubSpot Service Hub sandbox that reconciles cleanly and has been reviewed by real agents.
Keep these open
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Stand up a HubSpot Service Hub sandbox that matches production config
Create the custom fields, groups, brands, business hours and SLA policies first. A pilot into a default sandbox tests nothing, because the failures you care about are all configuration mismatches.
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Pick a deliberately nasty pilot sample
Take 500-1000 records chosen for difficulty, not convenience: the longest ticket threads, tickets with the most attachments, non-Latin character sets, merged and split tickets, deleted requesters, and every status value. A clean random sample proves only that easy records are easy.
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Run the load with masked data and instrument everything
Log every API request and response with its source record ID. When 40 records fail out of 10,000 you need to know exactly which ones and why, without re-running the whole batch.
PII Masker Never load real customer PII into a sandbox -
Measure real throughput against the rate limit
Record achieved records-per-hour under HubSpot Service Hub's actual rate limits, including retries and backoff. Extrapolate to the full volume: if the maths says the full load exceeds your freeze window, you fix that now, not on cutover night.
Published rate limits are ceilings, not throughput. Assume real-world rates are meaningfully lower once retries and backoff are counted.
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Reconcile the pilot and triage every failure
Diff source against target on record counts and field-level values. Every discrepancy gets a root cause and a fix — "probably fine" at pilot scale becomes thousands of broken records at full scale.
Migration Validation Tool Diff the pilot batch against source before scaling up -
Put real agents in front of the pilot data
Have two or three agents work sample tickets end to end in the sandbox. They find the things reconciliation cannot see: unreadable threading, missing context, macros that no longer make sense. Fix the mapping, then re-run.
Don't move on until
- Pilot batch reconciles to 100% on record counts
- Agents have reviewed sample tickets and confirmed they are workable
- Measured throughput extrapolates to a viable full-load window
05 Cutover Execute the switch inside a controlled, reversible window.
Objective All in-scope data live in HubSpot Service Hub, agents working in the new system, and a rollback path that stayed available throughout.
Keep these open
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Pre-load history before the freeze
Load closed tickets and contacts days or weeks ahead while Kustomer stays live. Only open tickets and the final delta need to move inside the freeze — this is the single biggest lever on window length.
Helpdesk Migration Planner Size the freeze window from HubSpot Service Hub's real API limits -
Publish the runbook with times, owners and abort criteria
A timed sequence: freeze start, final export, delta load, channel switch, smoke test, go/no-go, agent switch. Name who does each step and the explicit condition that triggers a rollback. Decide the abort criteria before the night, when nobody wants to be the one to call it.
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Freeze Kustomer and take the final delta
Stop new ticket creation, let agents finish in-flight replies, then export everything changed since the pre-load. Announce the freeze to the whole business, not just support — someone always tries to raise a ticket during it.
Tickets created during an unenforced freeze land in the old system and are the most common source of permanently lost data.
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Load the delta and open tickets
Run the delta load, then reconcile counts before touching any channel. Do not repoint email until the delta has verified — an inbound ticket arriving mid-load is far harder to untangle than a few extra minutes of freeze.
Migration Validation Tool Confirm the final delta landed before you reopen -
Repoint channels and verify with live traffic
Switch email forwarding and MX or connector settings, update chat widgets and web forms, and re-authorise integrations. Then send real test tickets through every channel and confirm each lands, routes and triggers the right automation.
Email forwarding changes can take up to a full DNS TTL to propagate — check the TTL days in advance and lower it if needed.
Cron Expression Builder Schedule the delta syncs that run through the freeze -
Run the go/no-go and switch the agents
Walk the exit criteria with the decision-maker, call it explicitly, then move agents over with a named person on hand for the first few hours. Keep Kustomer read-only rather than cancelled — cancelling the old contract on day one removes your only fallback.
Kustomer → HubSpot Service Hub specifics
- Big-bang
- works for organizations under 50K conversations with a clear cutover weekend. Freeze Kustomer Friday evening, run migration Saturday, validate Sunday, go live Monday.
- Phased/incremental
- is better for 100K+ conversations or teams that can't afford any downtime. Migrate historical data first (conversations older than 90 days), then run a delta sync of recent activity during cutover. The cutover window — when you freeze Kustomer, run the final delta, and switch agents to HubSpot — is typically 2–4 hours during off-peak.
- Rollback readiness
- Before cutover, confirm you can delete all imported records. HubSpot supports bulk deletion via POST /crm/v3/objects/{objectType}/batch/archive (up to 100 records per call). For large imports, batch deletion at the API's burst limit (190 requests/10 sec × 100 records/request) takes approximately 1 hour per 100K records. Archived records move to the recycling bin and are permanently deleted after 90 days. A clean rollback means re-running the migration from scratch, not surgically fixing records. Keep a rerunnable delta job so final cutover is a replay, not a one-shot gamble.
Don't move on until
- Full historical load complete and counts matched
- Inbound channels repointed and verified with live test tickets
- Rollback decision point passed explicitly, not by default
06 Validation Prove the migration is complete, then close it out.
Objective Documented evidence that data, workflow and reporting all survived, and a signed acceptance.
Keep these open
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Run the full reconciliation
Compare source and target on every object: total counts, counts by status, counts by group, attachment counts, and field-level spot checks on a random sample. Produce one report you can hand to an auditor.
Migration Validation Tool Reconcile Kustomer and HubSpot Service Hub record-for-record -
Verify field completeness, not just record counts
Re-profile the loaded data and compare null rates per field against the source profile. Matching record counts with a field that silently arrived empty is the failure mode counts alone will never catch.
Data Profiler Prove field completeness held up through the load -
Rebuild reporting and compare against baselines
Recreate your core dashboards — volume, first response time, resolution time, CSAT — and compare to pre-migration figures for the same period. Explain every variance; a changed SLA calculation is a real finding, not a rounding error.
SLA and first-response metrics are usually recalculated from the loaded timestamps, so they will differ if any timestamp mapping was approximate.
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Test the workflow layer end to end
Fire every trigger, automation, SLA escalation, macro and notification with a live ticket. Workflow does not migrate — it gets rebuilt — so it is untested until someone has actually watched it run.
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Confirm compliance and produce the audit trail
Re-scan the loaded data for regulated fields, confirm retention and deletion policies are configured in HubSpot Service Hub, and file the evidence with your PII decisions from the audit phase.
PII & Compliance Scanner Produce the compliance evidence your auditor will ask for -
Sign off, then decommission on a schedule
Get written acceptance against the Discovery success criteria. Keep Kustomer read-only for an agreed period (30-90 days is typical), take a final archive export, and only then cancel. Diarise the decommission date so it does not quietly renew.
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Record-count reconciliation
Compare total Customers in Kustomer vs. Contacts in HubSpot. Compare total Conversations vs. Tickets. Counts should match within 0.1% (the delta is usually merge-related). Segment validation windows so HubSpot Search's 10,000-result query cap does not hide discrepancies — use filterGroups with date ranges to partition counts.
Kustomer → HubSpot Service Hub specifics
- Field-level spot checks
- Sample 50–100 records across high-value customers. Verify custom field values, tags, assignees, and conversation statuses transferred correctly.
- Conversation thread integrity
- For 20+ sampled tickets, open the HubSpot ticket and verify every message appears in correct chronological order with correct sender attribution. This is the highest-value validation step.
- KObject verification
- If you migrated KObjects to HubSpot Custom Objects, verify associations: does each order/subscription link to the correct contact?
- Attachment spot check
- Open 10 tickets with known attachments. Verify files are accessible and not broken.
- UAT with agents
- Have 2–3 support agents work real tickets in HubSpot sandbox using migrated data. Ask them to confirm the data "feels right" — agents catch data quality issues that automated checks miss.
Don't move on until
- Full reconciliation report attached to the project record
- Reporting baselines match pre-migration figures within agreed tolerance
- Formal acceptance signed and archive retention scheduled
Field mapping reference
The field-by-field mapping for each object. Use this as the starting point for your mapping spec.
How Does Kus mer
| Kustomer field | HubSpot Service Hub field | Notes |
|---|---|---|
| Customer | Contact | Kustomer stores multiple emails/phones as JSON arrays; HubSpot uses a single primary email plus hs_additional_emails (semicolon-separated). Kustomer allows multiple customers with the same email if external IDs differ — HubSpot deduplicates by email, so you must merge before import. |
| Company | Company | HubSpot deduplicates by Company Domain Name. Association to Contacts must be rebuilt via the Associations API. |
| Conversation | Ticket | One ticket per conversation. Kustomer's status (open, snoozed, done) maps to HubSpot Ticket Pipeline stages. Conversation history lives in associated engagements. |
| Message (email) | Email Engagement | Map to POST /crm/v3/objects/emails with hs_email_direction, hs_email_text, hs_timestamp. |
| Message (chat/SMS/social) | Note Engagement | Default to notes unless you build a custom channel integration via HubSpot's custom channels API (/conversations/v3/custom-channels/{channelId}/messages). |
| Note (internal) | Note Engagement | Map to POST /crm/v3/objects/notes with hs_note_body (max 65,536 characters). |
| KObject (e.g., Order, Subscription) | Custom Object | Requires HubSpot Enterprise. Max 10 Custom Object definitions, 500K records each. If you're on Professional, flatten KObject data into custom properties on Contact or Ticket records. |
| Tag | Tag / Multi-select property | Tags flatten into a semicolon-delimited string or custom ticket properties. No global Kustomer-style tag model in HubSpot. |
| User (agent) | Owner | Users must be provisioned in HubSpot before the migration. Map Kustomer agent IDs to HubSpot Owner IDs for correct ticket assignment. |
| Team | Team | HubSpot Teams are configured in Settings; agents are assigned to teams via owner records. |
| Knowledge Base Article | Knowledge Base Article | HubSpot supports KB imports from CSV plus Freshdesk, Help Scout, Zendesk, and Intercom, with a limit of 400 articles per import. We did not find an officially documented public CRUD API for programmatic KB article creation. (knowledge.hubspot.com) |
| Business Rule / Workflow | Workflow | Cannot be exported from Kustomer. Must be rebuilt manually in HubSpot Workflows. |
| Saved Search | Active List / View | Cannot be exported from Kustomer. |
| Webhook configurations | Workflow + Custom Code / Operations Hub | Kustomer webhook endpoints and event subscriptions cannot be exported. Document each webhook's trigger, payload, and destination, then rebuild using HubSpot Workflows with webhook actions or Operations Hub custom code actions. |
Risk matrix
Per-object risk for this pair. Plan extra validation around anything marked high.
| Object | Risk | Notes |
|---|---|---|
| Contacts | medium | Kustomer stores multiple emails/phones as JSON arrays and allows duplicate emails with different external IDs, requiring pre-migration deduplication and field transformation to match HubSpot's single primary email model. |
| Companies | low | Company records map relatively cleanly, though HubSpot deduplicates by domain name and contact-to-company associations must be rebuilt via the Associations API. |
| Tickets (Conversations) | medium | Kustomer conversations map one-to-one to HubSpot tickets, but status values must be translated to pipeline stage IDs and the unified timeline context is lost in translation. |
| Conversation Transcripts (Messages) | high | Full message bodies are not available via CSV export and require per-conversation API extraction; non-email channels (chat, SMS, social) lack a direct engagement type and default to notes. |
| KObjects (Custom Objects) | high | KObjects require HubSpot Enterprise-tier Custom Objects with a cap of 10 definitions, and organizations on Professional must flatten this data into custom properties, risking loss of relational structure. |
| Tags | low | Tags can be flattened into semicolon-delimited strings or multi-select properties, though HubSpot lacks Kustomer's global tag model. |
| Users and Teams | low | Users must be pre-provisioned in HubSpot as Owners before migration, and Kustomer agent IDs mapped to HubSpot Owner IDs for correct ticket assignment. |
| Knowledge Base Articles | medium | HubSpot supports KB imports from CSV with a 400-article limit per import and lacks an officially documented public CRUD API for programmatic article creation. |
| Workflows and Business Rules | high | Kustomer Business Rules, Workflows, callable workflows, and webhook configurations cannot be exported and must be fully documented and manually rebuilt in HubSpot. |
| Reports and Dashboards | medium | Kustomer dashboards and custom analytics do not export; reports must be manually rebuilt in HubSpot's Custom Report Builder, with KObject-based reports requiring Enterprise-tier Custom Object reporting. |
The hard parts
What makes this specific migration difficult, beyond the mechanics.
Data Model Structural Mismatch
Kustomer's unified customer timeline architecture must be decomposed into HubSpot's separate relational objects—Tickets, Contacts, Companies, and Engagements—linked by associations, requiring significant schema translation.
Full Transcript Extraction
Kustomer's native CSV exports only include message previews, not full message bodies, so complete conversation transcripts must be extracted via per-conversation REST API calls.
KObject to Custom Object Mapping
Kustomer KObjects (orders, subscriptions, claims) require HubSpot Enterprise-tier Custom Objects, which are capped at 10 definitions and 500K records each, or must be flattened into custom properties on Professional plans.
Automation and Workflow Rebuild
Kustomer Business Rules, Workflows, Saved Searches, Snippets, and webhook configurations cannot be exported and must be manually documented and rebuilt in HubSpot Workflows.
Contact Deduplication Conflicts
Kustomer allows multiple customers with the same email address if external IDs differ, while HubSpot deduplicates contacts by email, requiring pre-migration merging to prevent data loss.
Multi-Channel Message Mapping
Kustomer messages from non-email channels (chat, SMS, social) have no direct HubSpot engagement equivalent and must default to Note engagements or require custom channel integration via HubSpot's custom channels API.
What breaks
Known failure modes. Have a recovery plan for each before you cut over.
Multi-channel conversations
A single Kustomer Conversation can include messages from email, chat, SMS, and social in one thread. HubSpot Tickets don't natively support mixed-channel threads. Each channel's messages become separate email or note engagements on the same ticket — the visual experience differs from Kustomer's unified thread.
Inline images
Images embedded directly in the body of a Kustomer email often break during export. Your script must parse the HTML body, identify src tags, download the images, upload them to HubSpot's File Manager, and rewrite the HTML src tags in the HubSpot Engagement payload.
Duplicate contacts
HubSpot strictly enforces unique email addresses for Contacts. Kustomer allows multiple Customer records with the same email via different channels. Your transform step must merge duplicates before import or HubSpot will reject the second and third profiles. Build deduplication logic in your staging environment.
KObject relationships
Kustomer KObjects can link to other KObjects (e.g., an Order links to a Subscription). HubSpot Custom Objects support associations with standard objects and other custom objects, but the association model is simpler — you lose multi-level nesting depth.
Attachment size limits
HubSpot's Files API accepts files up to 300MB. Kustomer attachments rarely hit this, but verify before bulk upload.
Old data access
Kustomer's standard Search API omits records updated more than two years ago. Use POST /v1/customers/archive/search for historical data beyond this window. (help.kustomer.com)
EU data residency
Kustomer offers EU hosting (api.prod2.kustomerapp.com). If your HubSpot portal is in a different region, confirm GDPR data transfer requirements before migrating. Standard Contractual Clauses (SCCs) or an adequacy decision may be required for EU-to-US data transfers. See our GDPR-compliant migration guide for the full framework.
Merged customers
Kustomer tracks customer merges. Use GET /v1/customers/{customerId}/merges during extraction to verify that merged records resolve correctly in HubSpot's single-email-per-contact model.
Tools used in this playbook
All free, all run entirely in your browser — nothing is uploaded.
FAQ
Can Kustomer conversation history be preserved in HubSpot Service Hub?
Yes, but only through API-based extraction. Kustomer CSV exports truncate message bodies to previews. Using the Kustomer REST API endpoint GET /v1/conversations/{id}/messages, you can extract full message bodies, timestamps, and channel data, then load them as email or note engagements in HubSpot with hs_timestamp set to the original creation time. Old omnichannel threads typically land as ticket-linked activities rather than native Help Desk threads.
Do I need HubSpot Enterprise to migrate from Kustomer?
You need HubSpot Enterprise only if your Kustomer organization uses KObjects (custom objects like orders, subscriptions, or claims). HubSpot Custom Objects require Enterprise on at least one Hub. If you don't use KObjects, HubSpot Professional is sufficient for Tickets, Contacts, Companies, and engagement history.
Is the native HubSpot Kustomer integration enough for migration?
No. HubSpot's marketplace listing for the Kustomer Data Sync app scopes the integration to customer data, not tickets. It is useful for profile sync during coexistence but not for a historical help desk migration with conversations, attachments, and KObjects.
What data is lost when migrating from Kustomer to HubSpot Service Hub?
Kustomer Business Rules, Workflows, Saved Searches, Snippets, and Shortcuts cannot be exported and must be rebuilt manually. HubSpot has no officially documented public CRUD API for Knowledge Base articles, so they require CSV import or manual recreation. The underlying support data (conversations, messages, attachments, KObjects) can be preserved via API extraction.
How long does a Kustomer to HubSpot Service Hub migration take?
A typical migration takes 2–4 weeks for organizations with under 100,000 conversations, including discovery, script development, pilot migration, validation, and cutover. Larger datasets with complex KObject schemas can extend to 4–6 weeks. The primary time driver is the number of per-conversation API calls required for full transcript extraction.