FullContact Identity Resolution API
Resolves fragmented identity signals (email, phone, social, MAIDs) into unified person and company profiles with employment, demographic, and social data for enrichment and identity verification use cases.
Score Breakdown
⚙ Agent Friendliness
🔒 Security
Bearer token auth via header is good practice. Handles PII — GDPR/CCPA documentation provided. SOC 2 Type II certified. No granular key scoping available.
⚡ Reliability
Best When
You need identity resolution that can stitch together multiple fragmented identifiers (email, phone, MAID) into a single unified profile with good social data coverage.
Avoid When
You need bulk B2B prospecting lists or very high match rates on sparse inputs — PDL or Clearbit may have broader professional data coverage.
Use Cases
- • Resolve an anonymous website visitor's email to a full professional profile including employer and job title for personalization agents
- • Enrich a CRM contact record by matching email address to current employment, location, and social handles
- • Verify whether two records with different emails represent the same person using the identity graph resolution capability
- • Look up a company domain to retrieve firmographic data including industry, size, description, and social profiles
- • Match mobile advertising IDs (MAIDs) to person profiles for audience enrichment in a marketing automation pipeline
Not For
- • High-volume real-time enrichment at millions of records — pricing and rate limits favor moderate enrichment volumes
- • FCRA-regulated use cases like employment screening or credit decisions — not a permissible purpose
- • Locating individuals by physical address for skip tracing or surveillance applications
Interface
Authentication
API key passed as a Bearer token in the `Authorization` header. Key is obtained from the FullContact dashboard after account creation.
Pricing
Free tier is useful for development and low-volume use cases. Paid plans provide access to deeper enrichment fields and higher rate limits.
Agent Metadata
Known Gotchas
- ⚠ A 404 response is expected when no profile is found — agents must treat this as a valid no-match result, not an error condition
- ⚠ Confidence scores on returned fields can vary significantly; low-confidence fields should not be used for automated decision-making
- ⚠ Social profile data (Twitter, LinkedIn URLs) can go stale — field presence does not guarantee current accuracy
- ⚠ The Resolve API (identity stitching) requires a PartnerID tag to work correctly; missing this in multi-touch scenarios breaks graph resolution
- ⚠ Lookup by phone number has notably lower match rates than email-based lookups — plan for high no-match rates on phone inputs
Alternatives
Full Evaluation Report
Detailed scoring breakdown, competitive positioning, security analysis, and improvement recommendations for FullContact Identity Resolution API.
Scores are editorial opinions as of 2026-03-06.