Unified Verification API: Integrating Checkr, Certn, and Background Check Providers Through One API
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A unified verification API normalizes background check and verification providers, including Checkr, Certn, First Advantage, Socure, Verifiable and Yardstik, behind one request, status, and results model, so a product orders checks through one integration instead of building each provider's API, approval process, and webhook semantics separately.
As of October 2026, Merge, Apideck, Kombo, Finch, Knit and Bindbee had no verification category; Kombo routes background-check vendors through its Assessment API, and Truto lists background-verification connectors without a unified API for them. Because the platform is pass-through, verification results, which can be FCRA-regulated consumer report data, reach your application without a copy of customer records at rest in Unified.to; connection credentials and operational metadata are encrypted at rest.
Background checks are unlike any other integration category. The data is consumer report data under the FCRA, including criminal history, identity verification results and adjudication outcomes, and every layer that transmits or stores it inherits obligations. The providers are consumer reporting agencies with credentialing processes, not self-serve APIs. And the products that need them usually need more than one.
This post covers who needs multiple verification providers, what direct integration with each actually requires, what compliance teams expect of any platform in the middle, and how a unified verification layer changes the build.
Who integrates more than one background check provider?
Single-provider products exist, but the platforms where verification is structural tend to outgrow one vendor:
ATS and HR platforms support multiple providers because their customers arrive with one. Greenhouse's support centre has an article titled "Using one or more background check providers", and SAP's knowledge base says SuccessFactors can run multiple background check vendors in one instance, using middleware that triggers each vendor by requisition status and template (both as of 23 October 2026). "Bring your own CRA" is a sales requirement, not a feature.
Staffing platforms and MSPs route by client program: different end-clients mandate different screening vendors and packages under the same platform.
Gig and marketplace platforms route by geography. Jurisdiction-specific rules and data sources mean even global providers have thin countries; a second regional provider covers what the primary can't.
Tenant screening and property management products mix check types, such as criminal, credit, eviction and identity, often sourced from different specialty providers.
The routing patterns are consistent: by work location, by customer, by check type or risk tier, with fallback rules when a provider has an outage or SLA problem. Each additional provider adds coverage, resilience, and pricing options; built directly, each one is a separate integration program.
What direct integration actually requires
The three major employment-screening providers have meaningfully different API models, and none is self-serve.
Checkr documents two distinct flows (as of 23 October 2026). The hosted invitation flow: you create a candidate and an invitation, and Checkr collects disclosures, consent, and missing PII directly from the candidate. The self-hosted flow: your product collects PII and consent itself and creates reports directly, which means your product collects and stores the candidate's information and consent, provides "state- and city-specific disclosures for each screening type", and goes through a review by your Checkr Partner Manager before approval. Either way, Checkr credentials each customer account, assessing "the validity of the business and its permissible purpose", before it can request checks, and production activity requires approval.
Certn's API documentation describes package endpoints, case ordering with an invitation email Certn sends to the applicant (or a returned invitation link), and webhooks for case status, check status and report-ready events. Demo accounts are requested from Certn's Partnership Team, and production access is requested by email to Certn's API support team (as of 23 October 2026).
First Advantage's developer documentation describes OAuth2 client credentials obtained through First Advantage, a separate set of production credentials, regional base URLs (US, EMEA, Canada, APAC), screening callbacks, and candidate invitations by email or link. Setup is supported by a team of First Advantage technical consultants, alongside Standard and REST APIs and file-based options (as of 23 October 2026).
Three providers, three approval processes, three webhook models, three report-retrieval mechanics, before any routing logic, and before compliance.
The compliance layer: what any intermediary must do
Your product isn't the consumer reporting agency, but a platform that orders, transmits, or displays consumer reports sits inside the FCRA ecosystem. Security and compliance teams evaluating any intermediary platform consistently require the same things: encryption in transit and at rest, strict tenant isolation and role-based access, access logging on every report view, masked identifiers (never full SSNs at rest), and, most consequentially, minimal retention: store only what's needed, typically report IDs, status, and high-level outcomes, with full reports viewed at the provider rather than persisted in intermediate systems.
That last expectation is the design pattern compliance-conscious platforms converge on: use provider-hosted candidate flows so the CRA collects SSNs and consent directly, keep status and outcomes in-app, and deep-link to the provider for the full report.
This is where architecture stops being a preference and becomes the compliance posture itself. Unified.to's pass-through architecture means verification requests and results route through to your application without being stored at rest in the integration layer: no criminal-history payloads, no identity-verification results, no report data sitting in intermediate infrastructure for a security review to scope. The best practice every compliance team asks intermediaries to approximate is the default behavior of the platform.
None of this transfers the legal responsibility that stays with the employer and your product: permissible purpose, written consent before ordering, and the pre-adverse/adverse action sequence when a report affects a decision. A verification layer moves data correctly; it does not make adjudication decisions, and any product building in-app adverse action workflows should involve legal counsel early.
What the unified flow looks like
Unified.to's Verification API normalizes the provider mechanics into two objects:
Package: each provider's catalog of checks, normalized (name, type, parameters, processing times, cost, score range, valid regions). Your product lists packages across connected providers through one call, which is what makes routing by geography, check type, or price a query instead of a per-vendor integration.
Request: the verification itself. Your product creates a Request against a package with the candidate's profile; the provider runs the check (using its own hosted candidate flow for consent and sensitive collection where applicable); status and results come back on the same object: status, score, completion timestamps, details, and report URLs, to the extent each provider's API provides them. Provider-specific fields remain available through raw passthrough.
One model for ordering, status, and results across 24 providers, including Checkr, Certn, Socure and First Advantage, with the per-provider depth documented in the published capability matrix rather than discovered mid-build. Result-field coverage varies by provider, because the providers' APIs vary; the matrix shows exactly which fields each one returns.
This is also, notably, the architecture the standard build-advice recommends: design an internal verification service layer with normalized candidate, package, order, status, and result concepts so providers can be swapped without rebuilding the product surface. The unified API is that layer, already built.
How is this different from IDV orchestration platforms like Alloy?
One adjacent category is easy to confuse with a unified verification API:
IDV orchestration platforms (Alloy, and risk platforms like Sardine) connect to identity-verification and data vendors, but their product is decisioning. As of 23 October 2026, Alloy describes an identity decisioning platform for banks and fintechs with 120+ data sources, step-up verification, case management and KYC/KYB, and its partner directory lists Socure, Entrust (formerly Onfido) and Veriff; Sardine describes a fraud and compliance platform with a no-code rule builder, integrated with 35+ data providers. Alloy is the right tool when the question is "should we approve this applicant"; a unified verification API is the right tool when the question is "give my product one integration for ordering checks and receiving results."
A unified verification API sits in the employment and screening workflow: the same platform's ATS, HR & Directory, and Assessments categories carry the candidate to and from the check. A screening platform can receive a recruiter-initiated order from an ATS through the Assessments API and fulfill it through any connected verification provider through this one: both sides of the pipeline, one platform, no consumer report data at rest anywhere between them. (For the ATS-side mechanics, see How Assessment and Background Check Vendors Integrate with ATS Platforms.)
How to choose
Integrate one provider directly if verification is your core product and one vendor matches your market; you get maximum provider-native depth (Checkr's hosted flows, adverse-action tooling) at the cost of being single-homed.
Integrate multiple providers directly if you need routing and you're prepared to own three approval processes, three API models, and the compliance surface of each, the path the largest platforms took before a unified layer existed.
Use a unified verification API if checks are structural but not your proprietary edge: one integration, normalized packages and requests across 24 providers, routing as configuration, and no consumer report data resting in the integration layer.
For most products, the durable pattern is the unified layer for coverage and the provider's own hosted candidate flows for consent and sensitive collection, the combination that minimizes both engineering surface and compliance scope at once.
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Frequently asked questions
Is there a unified API for background checks? Yes. Unified.to's Verification API covers background check and verification providers, including Checkr, Certn, First Advantage, Socure, Verifiable, and Yardstik, behind one package, request, status, and results model. As of October 2026, Merge, Apideck, Kombo, Finch, Knit and Bindbee had no verification category; Kombo routes background-check vendors through its Assessment API, and Truto lists background-verification connectors without a unified API for them.
Does a unified verification API store background check results? Unified.to does not. It keeps no customer records at rest, so background check results pass to your application without a stored copy; connection credentials and operational metadata are encrypted at rest.
Who is responsible for FCRA compliance when using a verification API? The employer ordering the check (and the product acting on its behalf) retains the core FCRA obligations regardless of integration path: permissible purpose, written consent before ordering, and the pre-adverse/adverse action process when a report affects a decision. The providers, as consumer reporting agencies, carry CRA obligations. An integration layer transmits data; it does not assume or transfer those responsibilities.
How is this different from Alloy or an IDV orchestration platform? Alloy orchestrates identity-verification vendors inside a risk-decisioning platform: rules, fraud models, case management for KYC in regulated fintech. A unified verification API is integration infrastructure: one normalized model for ordering checks and receiving results across providers, with the decisioning left to your product. Different question, different tool.
Can I route checks across providers by geography or price? That's the primary reason multi-provider setups exist. With normalized Package objects across providers, including regions, processing times, and cost fields, routing by work location, check type, or price becomes application logic over one API instead of per-vendor integrations.
Written by Mallory Greene.
About the author: Mallory Greene is Head of Marketing at Unified.to_. She writes about integration infrastructure, unified APIs, and MCP for technical teams. Based in Toronto._