There is no native migration path from Unthread to Help Scout. Plan on an API-to-API approach with schema translation, thread-type inference, and Slack-to-email identity resolution.
Migrating from Unthread to Help Scout is a complex API-to-API data translation project with no native or push-button migration path. Unthread is architecturally Slack-native, organizing data around Slack threads, channel-linked customer identities, and Slack user IDs, while Help Scout is email-first, structuring data around Mailboxes, email-identified Customers, and typed Conversation threads. Help Scout's official import tooling is powered by Import2, and Unthread is not on its published supported-source list, requiring use of the Mailbox API for any historical data load. Custom engineering work is required to resolve Slack identities to email addresses, infer thread types from sender metadata, re-upload attachments, and map Unthread's Ticket Type Fields and Accounts to Help Scout's more limited Custom Fields and Companies constructs.
Read this first
Pair-specific gotchas that catch teams out. Each one has cost somebody a weekend.
Help Scout custom fields are per-mailbox, not per-conversation-type
If you have multiple Unthread Ticket Types with different field schemas, you'll need to flatten them into a single set of custom fields on the Help Scout mailbox, or split across multiple mailboxes. Help Scout supports up to 10 custom fields per mailbox and up to 50 contact properties plus 50 company properties. (developer.helpscout.com)
The eventType enumeration above is based on observed values, not an exhaustive official list
Before running your migration, extract all unique metadata.eventType values from your Unthread messages and verify every type has a correct mapping. An unmapped event type defaults to "customer" thread, which may incorrectly expose internal messages to customers in Help Scout.
Timestamps are critical
You must explicitly pass the createdAt field for both the Conversation and individual Threads. If omitted, Help Scout will stamp all historical messages with the current date, destroying your historical timeline.
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 Unthread
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 Help Scout can hold your support model
Walk your current workflow through Help Scout: 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 Unthread → Help Scout 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.
Unthread → Help Scout specifics
- Channel shift
- The team is moving from Slack-centric support to email-centric support, and Unthread's Slack-native model no longer fits.
- Cost consolidation
- Teams already using Help Scout for external support want one platform rather than two.
- Workflow simplicity
- Help Scout's shared inbox model is lighter-weight for teams that don't need Slack-native intake, AI automations, or ticket type forms.
- Ecosystem fit
- Help Scout's integrations with Salesforce, HubSpot, and Jira (on Plus/Pro plans) align better with the team's stack.
- Multi-brand support
- Help Scout handles agency and multi-brand use cases with multiple mailboxes per account, which maps more naturally than a Slack-native tool for teams managing several brands.
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 Unthread 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 Unthread 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 Unthread 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
Unthread → Help Scout specifics
- Authentication
- X-Api-Key header with service account key
- Rate limits
- Not formally documented in public API reference. In testing, conservative pacing at 2–3 requests/second avoids throttling. Implement exponential backoff starting at 1 second on any HTTP 429 or 5xx response.
- API stability note
- The Unthread API is labeled Beta. Endpoint behavior may change without notice. Pin your extraction code to specific field names and validate responses against expected schemas. (docs.unthread.io)
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 Unthread → Help Scout 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 Unthread → Help Scout 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 Help Scout 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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Remove custom fields and tags
Delete any custom fields and tags created specifically for the migration via the Help Scout UI or API.
Unthread → Help Scout specifics
- Small team, <1K conversations, no custom fields
- Third-party tool or simplified API script.
- Custom Fields
- Create custom fields in the target mailbox to match your Unthread ticket type field mapping. Remember the 10-field-per-mailbox limit.
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 Help Scout sandbox that reconciles cleanly and has been reviewed by real agents.
Keep these open
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Stand up a Help Scout 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 Help Scout'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.
Unthread → Help Scout specifics
- Re-run from staging data
- Your staging database (JSONL files or SQLite) contains all extracted Unthread data. Fix the transformation logic, re-run the sandbox test, validate, then attempt the full load again.
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 Help Scout, 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 Unthread 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 Help Scout'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 Unthread 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 Unthread read-only rather than cancelled — cancelling the old contract on day one removes your only fallback.
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Identify affected records
Query your load log for all Help Scout conversation IDs created during the migration run.
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Delete customers
If you created new customers, delete them via DELETE /v2/customers/{id}. Note: this permanently removes the customer and all associated data.
Unthread → Help Scout specifics
- Bulk delete via API
- Use DELETE /v2/conversations/{id} for each migrated conversation. At ~100 effective write ops/min (Standard plan), deleting 10K conversations takes ~100 minutes.
- Partial rollback
- If only a subset of conversations failed, use the load log to identify failed IDs. Re-transform only those records and retry the load without deleting successful records.
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 Unthread and Help Scout 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 Help Scout, 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 Unthread 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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Rebuild Workflows
Unthread Automations don't migrate. Recreate routing rules, auto-assignment, SLA warnings, and escalation logic as Help Scout Workflows. Document each Unthread automation and its Help Scout equivalent before the cutover.
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Configure Beacon
If replacing Unthread's in-app chat widget, set up Help Scout's Beacon for live chat and knowledge base search.
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Update Integrations
Reconnect CRM (Salesforce, HubSpot), task managers, and other integrations. Point webhooks and API calls away from Unthread to Help Scout.
Unthread → Help Scout specifics
- Organize Knowledge Base
- If you migrated KB articles, arrange them into Help Scout Docs collections and verify HTML formatting renders correctly.
- Train the Team
- Help Scout's shared inbox model differs from Unthread's Slack-native workflow. Cover collision detection, @mentions, conversation assignment, saved replies, and the distinction between notes and replies.
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.
Object Equivalent
| Unthread field | Help Scout field | Notes |
|---|---|---|
| Customer | Customer | Map name + emailDomains → Help Scout customer with email |
| Account | Company | Unthread Accounts group customers; map to Help Scout Companies if on Plus/Pro. Account-level custom fields will be partially lost (Companies support limited properties). |
| Conversation | Conversation | Map status, subject, tags, timestamps |
| Message | Thread (customer/reply/note) | Infer thread type from sender role and metadata |
| Tag | Tag | Direct 1:1 mapping. Help Scout tags are case-insensitive and limited to 100 characters |
| Ticket Type | Custom Field + Tag | Ticket type name → tag; ticket type fields → custom fields |
| Ticket Type Field | Custom Field | Map field types carefully (see below) |
| Knowledge Base Article | Docs Article | Map title, content, status. Requires collection assignment in Help Scout. |
| User | User | Must be created in Help Scout UI or via SCIM (Pro only); map by email for conversation assignment |
| Automation | Workflow | Manual rebuild required — no automated mapping possible |
| Approval Request | Note (on conversation) | Archive as a note on the conversation for reference |
Unthread Help Scout
| Unthread field | Help Scout field | Notes |
|---|---|---|
| title | subject | Direct map; fallback to "(no subject)" if null |
| status (open/in_progress/on_hold/closed) | status (active/pending/closed) | open + in_progress → active; on_hold → pending; closed → closed |
| priority (3/5/7/9) | Custom field or tag | Help Scout has no native priority field. Map 3→Critical, 5→High, 7→Normal, 9→Low |
| createdAt | createdAt | Direct map (ISO 8601). Must be explicitly set or Help Scout stamps with current time. |
| closedAt | closedAt | Direct map |
| assignedToUserId | assignee (user ID) | Requires pre-mapping Unthread user IDs to Help Scout user IDs |
| customerId | customer | Map via email address resolved from Unthread customer record |
| tags | tags | Create tags in Help Scout first, then apply |
| ticketTypeFields | fields (custom fields) | Create custom fields in Help Scout mailbox first |
Ticket Type Fields Custom Fields
Unthread's per-ticket-type conditional custom fields cannot be faithfully represented in Help Scout's flat, 10-field-per-mailbox Custom Fields model, requiring schema redesign and likely data loss for complex field configurations.
| Unthread field | Help Scout field | Notes |
|---|---|---|
| short-answer | Text | Direct map |
| long-answer | Text | Help Scout text fields have character limits |
| single-select | Dropdown | Map options 1:1 |
| multi-select | Dropdown (single-select only) | Help Scout dropdowns are single-select. Concatenate values into a pipe-delimited string, or split into multiple fields if count allows |
| checkbox | Dropdown or Tag | No native checkbox in Help Scout custom fields. Map true/false to a dropdown with "Yes"/"No" options |
| user-select | Text or Dropdown | Store user name/email as text |
Risk matrix
Per-object risk for this pair. Plan extra validation around anything marked high.
| Object | Risk | Notes |
|---|---|---|
| Conversations | high | Conversations require full API-to-API extraction and transformation with no native import path, and Help Scout's 100-thread-per-conversation limit can truncate long Unthread threads, causing irreversible data loss on high-volume tickets. |
| Message Threads | high | Unthread messages must have their type inferred from sender role and partially-undocumented metadata rather than an explicit field, making correct classification of customer, reply, and internal note threads a high-risk transformation step. |
| Contacts / Customers | high | Unthread customer identity is Slack-channel-linked rather than email-based, so every customer record requires Slack-to-email identity resolution before it can be created in Help Scout's globally unique email-keyed customer model. |
| Attachments | medium | Attachments are migratable via download-encode-upload sequences but introduce significant volume-dependent complexity and are silently dropped by low-fidelity migration methods such as CSV import or middleware platforms. |
| Custom Fields / Ticket Type Fields | high | Unthread's per-ticket-type conditional custom fields cannot be faithfully represented in Help Scout's flat, 10-field-per-mailbox Custom Fields model, requiring schema redesign and likely data loss for complex field configurations. |
| Tags | low | Tags exist as a concept in both platforms and can be mapped and applied during conversation creation via the Help Scout API with relatively straightforward transformation logic. |
| Accounts / Companies | medium | Unthread Accounts carry custom fields and rep assignments that exceed Help Scout Companies' limited property model, meaning organizational grouping can be partially preserved but account-level custom metadata will likely be lost. |
| Users / Agents | medium | Unthread users are synced from Slack workspaces while Help Scout users must be manually invited or provisioned via SCIM on Pro plans, requiring pre-migration user setup and Slack-to-email mapping to preserve agent attribution on historical conversations. |
| Automations / Workflows | high | Unthread's event-driven, webhook-triggered, and scheduled automation model has no structural equivalent in Help Scout's rule-based if/then Workflows, requiring full manual recreation and functional redesign of all automation logic. |
| Knowledge Base Articles | medium | Unthread's API-managed, AI-indexed Articles and Help Scout's Docs collections use different organizational hierarchies and delivery models, so content can be migrated via API but AI indexing behavior and site structure must be manually reconfigured in Help Scout. |
The hard parts
What makes this specific migration difficult, beyond the mechanics.
Slack Identity Resolution
Every Unthread customer and agent is identified by a Slack user ID, which must be resolved to a valid email address before any conversation can be correctly attributed to a Help Scout Customer record.
Thread Type Inference
Unthread messages carry no explicit type field, so migration logic must infer whether each message is a customer message, agent reply, or internal note by examining sender role, the isPrivateNote flag, and partially-documented metadata.eventType values.
Attachment Re-Upload at Scale
Every file attachment must be downloaded from Unthread's file endpoint, base64-encoded, and embedded into Help Scout thread payloads, creating compounding overhead that can reach tens of thousands of discrete file operations on datasets with average attachment rates.
Custom Field Model Mismatch
Unthread's Ticket Type Fields support conditional logic and are scoped per ticket type, while Help Scout Custom Fields are capped at 10 per mailbox with no conditional logic, requiring significant data restructuring and potential loss of field fidelity.
Rate Limit Asymmetry
Help Scout counts write requests as double toward its plan-based rate limits, capping effective write throughput at approximately 100 operations per minute on the Standard plan, while Unthread's cursor-paginated API has no formally documented rate limits requiring empirical validation.
Account and Relationship Mapping
Unthread's Account objects group customers with assigned reps and custom properties, but Help Scout's Companies construct is a lightweight grouping with limited custom properties, meaning organizational hierarchy and account-level metadata cannot be fully preserved.
Tools used in this playbook
All free, all run entirely in your browser — nothing is uploaded.
FAQ
Can I migrate Unthread conversations to Help Scout without coding?
Not with full fidelity. Third-party tools like Help Desk Migration offer a no-code wizard, but Unthread is not on Help Scout's published supported-source list for its Import2-powered import flow. For full conversation history with attachments and thread structure, an API-based migration or managed service is required.
What is the Help Scout API rate limit during a migration?
Help Scout enforces plan-dependent rate limits — up to 200/400/800 requests per minute on Standard/Plus/Pro plans. Write requests (POST, PUT, DELETE, PATCH) count as 2 requests toward the limit. Exceeding the limit returns HTTP 429 with a Retry-After header.
Does Help Scout have a thread limit per conversation?
Yes. Help Scout enforces a hard limit of 100 threads per conversation. If an Unthread conversation has more than 100 messages, you need to truncate or split it into multiple Help Scout conversations.
How do I handle Unthread customers with no email when migrating to Help Scout?
Help Scout requires an email address for every customer. For Unthread customers who only interact via Slack, generate a placeholder email (e.g., slack-user-{slackId}@migration.placeholder), tag these records, and resolve the emails post-migration.
How long does an Unthread to Help Scout migration take?
Depends on volume and complexity. A small dataset under 5K conversations typically takes 1–3 days with a tested API script. Larger datasets (50K+) with attachments and custom fields can take 1–2 weeks including extraction, transformation, loading, and validation.