Bullhorn-to-Crelate migrations are bottlenecked by Crelate's 120 req/min API limit and 20 custom fields per entity cap. Plan for data model compression, not just field mapping.
Technical guide to migrating from Bullhorn to Crelate: API rate limits, data model mapping, custom field constraints, and step-by-step migration process for CTOs.
Read this first
Pair-specific gotchas that catch teams out. Each one has cost somebody a weekend.
Crelate deprecated API v1 and v2 endpoints as of November 1, 2025, throttling them to 30
Crelate deprecated API v1 and v2 endpoints as of November 1, 2025, throttling them to 30 requests per minute. All new migration scripts must target API v3. If you're reusing old integration code, rewrite it before starting. (postman.com)
Bullhorn is purpose-built for high-volume, transactional staffing with deep back-office
Bullhorn is purpose-built for high-volume, transactional staffing with deep back-office integrations (payroll, VMS, credentialing). If your agency depends on Fieldglass/Beeline VMS integrations or Bullhorn Back Office, Crelate may not be a like-for-like replacement. Audit your integration dependencies before committing.
Bullhorn API access is not included in the ATS Growth (formerly Team Edition) tier
If you are on this plan, you must rely on manual CSV exports or upgrade to Corporate/Enterprise editions to use the REST API for migration. (kb.bullhorn.com)
Crelate's documentation explicitly warns that repeated error status codes (400, 401, 403,
Crelate's documentation explicitly warns that repeated error status codes (400, 401, 403, 500) will aggressively trigger rate limiting. If your script attempts to link a Placement to a Job UUID that failed to create in a previous step, Crelate returns a 400. If this happens in a loop, your IP will be throttled entirely, halting the migration.
Build your crosswalk table before the first test run
A crosswalk is a persistent map from Bullhorn integer IDs to Crelate GUIDs. Without it, retries create duplicates and validation becomes guesswork.
Do not PATCH Crelate tags as if they were additive
Crelate documents tag updates as full replacement: any tags omitted from the update payload are lost.
The runbook
Work top to bottom. Tick steps as you go — your progress is saved in this browser.
01 Discovery Scope candidates, pipelines and the compliance obligations that come with them.
Objective Agreed scope across candidates, applications, jobs and interview history, with legal signed up on retention.
Keep these open
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Inventory every object in Bullhorn
Count candidates, applications (a candidate can have many), jobs and requisitions, interviews, scorecards, offers, and resume files. Applications and scorecards usually outnumber candidates several times over, and resume files dominate storage.
Data Profiler Get real record counts instead of estimating from memory -
Settle retention and consent with legal
Candidate data is heavily regulated: GDPR right-to-erasure, EEOC/OFCCP record-keeping, and per-region retention windows that conflict with each other. Decide what may be migrated at all before you scope anything else — this frequently shrinks scope substantially.
Migrating candidate records whose consent has lapsed or whose retention window has expired creates a new compliance breach in the target system.
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Map the hiring pipeline and agree the target stages
Document every job's pipeline, stage, and rejection reason, then agree the Crelate model with talent leadership. Stage definitions drive every funnel metric you report, so changing them silently rewrites your hiring analytics.
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Catalogue integrations and the job-board estate
List job boards, careers-site integration, HRIS, background check, assessment platforms, calendar and email. The careers site and job boards are customer-facing, so their cutover needs its own plan and its own testing.
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Build the business case and choose the window
Model licence delta, effort and recruiter productivity dip. Time the window against your hiring cycle: a migration during peak graduate recruitment or a hiring surge will fail on people, not technology.
Vendor Evaluator Score Crelate against alternatives on weighted criteria -
Record count comparison
Bullhorn entity count vs. Crelate entity count per type
Bullhorn → Crelate specifics
- UI and recruiter adoption
- Crelate delivers a modern, intuitive interface compared to Bullhorn's steeper learning curve. A common framing from agency operators: "Crelate is Bullhorn for people who hate Bullhorn's interface."
- Implementation speed
- Crelate advertises a 14-day implementation timeline. Bullhorn implementations, especially for multi-division agencies, frequently take 6–12 weeks.
- Agency fit
- Crelate's integrated ATS+CRM works well for small-to-midsize staffing firms (3–50 recruiters) that don't need Bullhorn's VMS integrations, back-office suite, or enterprise compliance features.
Don't move on until
- Counts confirmed for candidates, applications, jobs and offers
- Retention and consent obligations confirmed with legal
- Hiring-stage model agreed with talent leadership
02 Data Audit Audit candidate data with compliance sitting next to you.
Objective Profiled exports with duplicates, expired records and resume files all quantified and triaged.
Keep these open
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Export and profile candidates, applications and jobs
Profile each object separately and reconcile against API counts. Watch the candidate-to-application ratio: a mismatch usually means applications have been silently truncated by pagination.
Data Profiler Profile the Bullhorn export for nulls, outliers and type drift -
Quantify duplicate candidates and agree survivorship
The same person applies repeatedly over years with different emails and name spellings. Measure the duplicate rate and agree survivorship rules — which record wins and what happens to the application history attached to the losers.
Merging candidates without agreed survivorship rules destroys application and interview history that you may be legally required to retain.
Data Cleaner Strip empty rows, stray whitespace and dead columns -
Identify records outside their retention window
Flag candidates whose consent has expired, who have exercised erasure, or who fall outside regional retention. Exclude them from scope and document the exclusion — you need to show the decision was deliberate.
PII & Compliance Scanner Find regulated fields before they land in a new system -
Inventory resume files and attachments
Count files, total volume and MIME types, and check every attachment still resolves to a live URL. Expiring signed download URLs are the classic reason a resume migration completes with a large fraction of empty files.
Resume download URLs are often short-lived signed links. Fetch files close to load time or they will 404 mid-migration.
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Verify relationship integrity
Confirm every application links to a live candidate and a live job, and every scorecard to a real interview. Orphaned applications produce a funnel report that does not tie to anything.
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Clean, normalise and produce masked test data
Normalise emails, phone formats and locations, standardise timestamps to UTC, and generate a masked dataset for the sandbox. Real candidate data in a sandbox is a compliance breach in most jurisdictions.
PII Masker Generate a safe copy for sandbox and vendor testing
Bullhorn → Crelate specifics
- Relationship integrity audit
- For every Placement, verify the linked Contact and Job exist and are correct.
Don't move on until
- Duplicate candidate rate quantified with a merge policy agreed
- Records outside retention identified and excluded
- Resume and attachment inventory complete with total volume
03 Field Mapping Map the candidate-application-job triangle before anything else.
Objective A signed mapping covering objects, stages, rejection reasons, scorecards and EEO fields.
Keep these open
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Map the candidate, application and job model
ATS platforms differ on whether a person or an application is the primary record. Establish this first: getting it wrong means one candidate becomes five, or five applications collapse into one, and the entire field map has to be redone.
Candidate-centric and application-centric models are not interchangeable. Confirm which Crelate uses before mapping any field.
Schema Mapper Match Bullhorn fields to Crelate by uploading both schemas -
Map pipeline stages and rejection reasons exhaustively
Enumerate every stage and rejection reason across all jobs, including retired values on historical applications, and map each explicitly. Unmapped rejection reasons are both a reporting gap and, in regulated hiring, a compliance one.
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Decide EEO and diversity data handling
These fields are separately regulated and often legally required to be stored apart from the candidate record. Confirm with legal whether they migrate at all, and how Crelate isolates them.
EEO data usually cannot be migrated into ordinary custom fields without breaching the segregation rules that govern it.
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Map interviews, scorecards and feedback
Structured scorecards rarely have a native equivalent. Decide whether to reconstruct them, flatten them into notes, or keep them only in the archive — and be explicit that flattening loses the ability to report on them.
JSON to CSV Converter Flatten nested API responses into a reviewable sheet -
Plan resume and file migration
Confirm size limits, MIME support and whether Crelate re-parses resumes on upload. Re-parsing can overwrite carefully curated candidate fields with worse machine-extracted values, so test it deliberately.
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Set load order and freeze the spec
Users, then jobs, then candidates, then applications, then interviews and scorecards, then files. Keep source IDs in custom fields, then version and sign off the spec.
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Normalize picklists
Bullhorn picklist values must match Crelate's configured picklist options, or be pre-created in Crelate Settings before migration. Creating new custom picklist fields is not supported by the Crelate API — configure them in the UI. (postman.com)
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Convert dates
Bullhorn returns timestamps as epoch milliseconds. Crelate requires ISO 8601 UTC strings.
Data Format Converter Reshape the export into the format Crelate's importer expects -
Merge Candidates and ClientContacts
Both become Crelate Contacts. Use tags (e.g., {"Default": ["Candidate"]} vs {"Default": ["Client Contact"]}) to differentiate.
Bullhorn → Crelate specifics
- Consolidate custom fields
- Map Bullhorn's customText1–customTextN into Crelate's 20 custom field slots. Serialize overflow fields into a structured JSON note.
- Detect duplicates
- The same person can exist as both a Candidate and a ClientContact in Bullhorn. Merge by email or name+phone, preserving the most complete data from each.
- Prioritize the 20 most-used fields
- for Crelate's custom field slots. Archive the rest into a structured note or external system.
- Concatenate related fields
- (e.g., merge "Clearance Level" and "Clearance Expiry" into a single Crelate custom field).
Don't move on until
- Candidate/application/job model mapped and reviewed
- Every stage and rejection reason explicitly mapped
- EEO and diversity field handling agreed with legal
04 Test Migration Pilot whole candidate journeys, not isolated records.
Objective A sandbox pilot where candidate journeys, funnel metrics and resume files all verify.
Keep these open
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Configure the Crelate sandbox with the agreed pipelines
Create jobs, pipeline stages, scorecard templates, user roles and custom fields first. Loading applications before the stages exist puts every candidate in a default stage and invalidates the pilot.
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Select complete candidate journeys as the pilot slice
Take 100-200 candidates with all their applications, interviews, scorecards and files — including repeat applicants, hires, rejections at every stage, and candidates on multiple jobs. Repeat applicants are where the model mapping actually gets tested.
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Run the load in dependency order with logging
Jobs, candidates, applications, interviews, then files, logging each request against its source ID. Track file uploads separately: they fail for different reasons and at different rates than record writes.
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Verify journeys and funnel metrics
Confirm each candidate sits at the right stage on the right job with their history intact, and that per-stage funnel counts match Bullhorn for the pilot jobs. Funnel mismatches point straight back to stage mapping.
Migration Validation Tool Diff the pilot batch against source before scaling up -
Open every pilot resume and check re-parsing
Actually open the files rather than trusting the upload count, and check whether re-parsing has overwritten any candidate fields. A resume that uploaded as a zero-byte file still counts as a success in most logs.
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Put recruiters in front of the pilot data
Have recruiters work their own pilot requisitions end to end. They immediately spot missing feedback, wrong stages and unreadable history that reconciliation cannot see.
Don't move on until
- Candidate-application-job relationships intact for the pilot
- Funnel counts per stage match source for pilot jobs
- Resume files open correctly for every pilot candidate
05 Cutover Switch recruiting without dropping a live candidate.
Objective All in-scope recruiting data live in Crelate, careers site and boards repointed, recruiters working.
Keep these open
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Pre-load historical candidates and closed jobs
Load closed requisitions, rejected candidates and archived applications while Bullhorn stays live. Only active pipeline and the final delta need to move in the window.
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Publish the runbook including the careers-site switch
A timed sequence with owners and abort criteria, treating the careers site and job boards as first-class steps. They are candidate-facing, so a failure there is publicly visible in a way a data defect is not.
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Freeze Bullhorn and take the final delta
Stop new applications and let recruiters finish in-flight actions, then export everything changed since the pre-load. Coordinate with anyone actively interviewing so feedback is not entered into the old system mid-freeze.
Interview feedback entered in the old ATS during the freeze is lost, and it is the data recruiters most immediately notice missing.
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Load active pipeline and reconcile stages
Load active candidates and applications, then verify every active candidate is at the correct stage on the correct job before repointing anything. Active-stage accuracy is what recruiters check first on day one.
Migration Validation Tool Confirm the final delta landed before you reopen -
Repoint careers site, job boards and integrations
Switch the careers-site integration, repost or migrate live job ads, and repoint HRIS, background check, assessment and calendar integrations. Then submit a real test application through the careers site and every major board.
Job ads left posted against the old ATS keep collecting applications that never reach the new system.
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Go/no-go and switch recruiters over
Call the decision against the exit criteria, then move recruiters with support on hand for the first day. Keep Bullhorn read-only — candidate records have retention obligations that outlast the migration.
Bullhorn → Crelate specifics
- Attachment spot check
- Download 20 random files from Crelate and compare to Bullhorn originals.
Don't move on until
- Historical load complete and reconciled before the freeze
- Careers site and job boards posting into Crelate and verified
- Active candidates confirmed at the correct stage
06 Validation Prove the funnel, the files and the compliance position.
Objective Reconciled recruiting data, funnel parity with baseline, and a defensible compliance record.
Keep these open
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Reconcile every object including files
Compare counts for candidates, applications, jobs, interviews, scorecards and files, with field-level spot checks on a sample. Count files separately — they are the object most likely to be quietly short.
Migration Validation Tool Reconcile Bullhorn and Crelate record-for-record -
Tie funnel and time-to-hire reporting to baseline
Rebuild funnel conversion, time-to-hire, source effectiveness and offer-acceptance reporting and compare to pre-migration figures. Variances trace back to stage mapping and to how application timestamps were handled.
Time-to-hire depends on stage-transition timestamps. If those were approximated, the metric will differ even with identical records.
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Verify file integrity at scale
Sample-open resumes across the whole load and compare file sizes against source. Zero-byte and truncated files are common and never surface in an upload success count.
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Confirm retention, consent and EEO configuration
Verify retention rules, consent state and EEO segregation are correctly configured in Crelate, and that excluded records genuinely did not migrate. File this as your compliance evidence.
PII & Compliance Scanner Produce the compliance evidence your auditor will ask for -
Test workflow, notifications and candidate-facing paths
Fire every stage automation, interview scheduling flow, rejection template and offer approval, and submit a live application through the careers site. Candidate-facing emails going out wrong is a brand problem, not just a bug.
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Sign off and schedule decommission
Get written acceptance against the Discovery criteria, retain Bullhorn read-only for the period your retention policy requires, take a final archive export, and diarise cancellation.
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Record count reconciliation
Total records per entity type in Bullhorn vs. Crelate. Tolerance: 0% variance.
Bullhorn → Crelate specifics
- Field-level sampling
- Pull 50 random records from each entity type, compare field values against Bullhorn source
- Relationship integrity
- Verify that every Placement links to a valid Contact and Job
- Attachment verification
- Spot-check that resumes/files are accessible on the correct Contact records
- Field-level validation
- Sample 5% of records per entity type. Compare every mapped field value.
- Picklist validation
- Ensure all migrated picklist values match Crelate's configured options.
Don't move on until
- Reconciliation complete across candidates, applications and files
- Funnel and time-to-hire reporting tie to baseline
- Retention and EEO configuration verified, acceptance signed
Field mapping reference
The field-by-field mapping for each object. Use this as the starting point for your mapping spec.
Entity Equivalent
| Bullhorn field | Crelate field | Notes |
|---|---|---|
| Candidate | Contact (with candidate tag/status) | Crelate uses a unified Contact record; candidates are differentiated by workflow status and tags |
| ClientContact | Contact (with client tag) | Same entity type — use tags or custom fields to distinguish from candidates |
| ClientCorporation | Company | Direct mapping; parent/child company hierarchies require manual reconstruction |
| JobOrder | Job | Stages map to Crelate workflow stages; Crelate supports up to 30 stages (Enterprise) |
| JobSubmission | Pipeline stage on a Job | No direct equivalent — submissions become Contacts placed at a stage on a Job's pipeline |
| Placement | Placement | Crelate has native Placement records with bill/pay rate support |
| Opportunity | Opportunity (Sales Pipeline) | Choose the correct Opportunity Type at creation — Crelate does not allow changing it after creation (help.crelate.com) |
| Lead | Opportunity or Contact | Depends on pipeline stage; early-stage leads → BD Pipeline, qualified leads → Sales Pipeline |
| Note | Note | Direct mapping; attach to appropriate parent entity by ID |
| Appointment | Activity | Map to Crelate's activity types (Meeting, Call, etc.) |
| Task | Task | Direct mapping; Crelate tasks attach to Contacts, Jobs, or Companies |
| Custom Objects | No direct equivalent | Must be flattened into custom fields (max 20), tags, or serialized into notes |
| FileAttachment | Document / Artifact | Migrate in a separate binary pass via API |
Bullhorn Crelate
| Bullhorn field | Crelate field | Notes |
|---|---|---|
| firstName | FirstName | Direct map |
| lastName | LastName | Direct map |
| Direct map | ||
| phone | Phone | Direct map |
| status | EntityStatus | Map values to Crelate statuses |
| source | Source | Direct map |
| owner.id | PrimaryOwner_Id | Map via user ID table |
| dateAdded | CreatedOn | Convert epoch → ISO |
| customText1–customText20 | CustomFields.{logical_name} | Map first 20; serialize remainder into notes |
| skills.name | Tags.Skills | Convert skill associations to tag array |
| address.city | City | Direct map |
| salary | Custom field | Map to a custom field slot |
| clientCorporation.id | Company_Id | Map via company crosswalk table |
| Candidate.id | Custom field or crosswalk | Store Bullhorn ID for replay and dedupe |
| JobOrder.numOpenings | Opportunity openings | Default null to 1 only if business agrees |
Tools used in this playbook
All free, all run entirely in your browser — nothing is uploaded.
FAQ
How long does a Bullhorn to Crelate migration take?
A CSV-only migration of small, flat data can complete in 1–3 days. API-based migrations with relationship preservation typically take 2–6 weeks for DIY builds or 3–5 business days with a managed migration service, depending on data volume and complexity.
What are the Bullhorn and Crelate API rate limits?
Bullhorn allows up to 1,500 requests per minute and 100,000 API calls per month (unless negotiated). Crelate API v3 enforces 120 requests per minute per IP address. Deprecated v1/v2 endpoints are throttled to 30 req/min. Repeated error codes on Crelate trigger even more aggressive throttling.
Can I migrate Bullhorn custom objects to Crelate?
Not directly. Crelate does not support custom objects. Bullhorn custom objects (up to 35 per Person entity) must be flattened into Crelate's custom fields (max 20 per entity), tags, notes, or activity records during transformation.
What Bullhorn data is lost in a CSV export?
CSV exports from Bullhorn flatten relational data, losing all Candidate-to-JobSubmission-to-Placement relationships, file attachments, custom object data, and activity history. Only fields visible in your current list view columns are included.
Does Bullhorn's ATS Growth plan support API access for migration?
No. Bullhorn's ATS Growth edition (formerly Team Edition) does not include API access. Users on this plan must rely on CSV exports or upgrade to Corporate/Enterprise editions to use the REST API.