15 Payroll APIs to Integrate With in 2026: ADP, Gusto, Paychex
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The payroll APIs SaaS products commonly integrate with include ADP, Gusto, Paychex, Paylocity, Paycor, Deel, Rippling, Remote, Dayforce and Workday. This list covers 15 payroll systems with APIs: what each vendor documents, how access works and where the documentation lives, checked against each vendor's own pages on 20 October 2026, for developers deciding which payroll systems to support. Unified.to reads payroll data from many of them through its HR & Directory API across 683 integrations; for the payroll data model (pay runs, payslips, earnings and deductions), see What Is Payroll Integration?
What is a payroll API?
A payroll API allows applications to access payroll and compensation data programmatically.
Payroll APIs typically have endpoints for:
- employee payroll profiles
- compensation and salary data
- payroll runs and payment history
- tax withholdings and compliance reporting
- deductions and benefits contributions
- direct deposit and bank accounts
- contractor payments
- timesheets and hours worked
SaaS products use them for:
- payroll synchronization with HR systems
- benefits and compensation management
- workforce analytics dashboards
- accounting and finance reconciliation
- employee financial wellness tools
- contractor and global payroll automation
Because payroll systems often act as the financial system of record for employee compensation, payroll integrations are foundational for many SaaS products.
Why do SaaS products integrate with payroll APIs?
SaaS products integrate with payroll APIs because payroll is the record of what each person was paid, and benefits, accounting reconciliation, analytics and employee-finance features all depend on it.
Common use cases include:
Payroll automation
Sync payroll runs, payment status, and employee compensation data automatically across systems.
Benefits and deductions management
Track deductions for benefits programs, retirement contributions, and taxes across payroll providers.
Financial reporting and reconciliation
Read payroll data into accounting systems or analytics tools to produce financial reports.
Global workforce payments
Automate payments for contractors and international employees.
Employee financial tools
Build applications that help employees track income, taxes, and benefits.
Which payroll APIs do developers integrate with?
The 15 payroll APIs below each list what the vendor documents and how API access works, checked against the vendor's own pages on 20 October 2026.
ADP API
ADP gives payroll API access two ways: partners build apps for ADP Marketplace, and ADP Workforce Now clients can buy ADP API Central to build their own integrations. Connections use mutual TLS and OAuth 2.0, and the client sets what each integration can read and write (as of 20 October 2026).
Gusto API
Gusto has two API programs. Gusto Embedded lets you build payroll into your own product; App Integrations is for apps that read and write a mutual customer's Gusto account (as of 20 October 2026).
Paychex API
Paychex runs a developer program with separate access paths for Paychex clients and for partners; the API catalogue is behind "See available APIs" on its developer centre (as of 20 October 2026).
Paylocity API
Paylocity issues OAuth credentials once API access is approved. A demo environment requires an existing Paylocity customer, or one taking part in early-adoption testing; technology partners apply through Paylocity's Partner Relations team (as of 20 October 2026).
Paycor API
Paycor lists more than 140 APIs in its developer tools (as of 20 October 2026). Paycor's site links Paychex's agreement to acquire Paycor.
Deel API
Deel's REST API authenticates with a bearer key from the Deel app. For payroll, it covers payroll inputs, contractor onboarding and contractor payments, with webhooks for payments, timesheets and approvals (as of 20 October 2026).
Rippling API
Rippling runs payroll for employees and contractors alongside its HR and IT products. Its developer site documents a REST API with OAuth installation for partner apps and API scopes (as of 20 October 2026).
QuickBooks Payroll API
Intuit documents a QuickBooks Payroll API and a Payroll and Time API on its developer site (as of 20 October 2026). Check its payroll docs for the data and scopes your app can use.
Remote API
Remote's API uses OAuth 2.0; some endpoints need a token from a company manager's authorization rather than an integration token. For payroll it covers payslips, payroll calendars and incentives, alongside employments, contractors and time off, with a sandbox for testing (as of 20 October 2026).
Dayforce API
Dayforce (formerly Ceridian) sells HR, pay, time and talent software. Its developer portal has API documentation and an API explorer; you sign up there to get API keys (as of 20 October 2026).
Workday Payroll API
Workday Payroll is part of Workday's HCM products. Payroll data is reached through Workday's SOAP API (Workday Web Services) and REST APIs (as of 20 October 2026).
Sage API
Sage sells payroll in several products, including Sage HR & Payroll and Sage HCM, and links its developer documentation from sage.com (as of 20 October 2026).
TriNet API
TriNet's HR Platform (formerly Zenefits) has a mostly read-only API: people, employments, departments, locations, bank accounts and time off. Its docs list no payroll endpoints (as of 20 October 2026). Apps authenticate with OAuth and go through TriNet's integration partner program; a company can also build a custom integration for its own data.
PayFit API
PayFit customers on Standard or Premium plans create API keys from their PayFit dashboard (PayFit, last updated April 2024). PayFit doesn't link public API documentation from that page.
Payworks API
Payworks is a Canadian payroll, HR and time company. As of 20 October 2026, its developer portal lists REST APIs for payroll, employees, time management and absence management. Access needs a Payworks account, an API key and a signed licence agreement, and the customer's Payworks representative enables it.
Payroll sits next to HR and time systems. For HR systems, see 25 HRIS APIs to Integrate With in 2026; for scheduling and time tracking, including Deputy, see 15 Workforce Management APIs to Integrate With in 2026.
What makes payroll APIs hard to integrate?
Payroll APIs are hard to integrate at scale because each vendor differs in access rules, authentication and data model, and every record carries compensation, tax and bank data.
Security and compliance requirements
Payroll data includes highly sensitive information such as compensation, tax identifiers, and bank accounts. Integrations must meet strict security and compliance requirements.
Authentication differences
Payroll vendors use different authentication: Paylocity issues OAuth credentials, PayFit uses API keys, and ADP requires mutual TLS with OAuth 2.0 (as of 20 October 2026).
Inconsistent payroll schemas
Payroll objects differ significantly across providers. Compensation, deductions, taxes, and benefits structures vary widely.
API version changes
Vendors version their APIs and change them on their own schedule, so each integration needs upkeep.
Rate limits and job processing
Pay runs are batch processes, so integrations deal with asynchronous jobs and queues.
Global payroll complexity
Handling payroll across jurisdictions introduces tax, compliance, and currency challenges.
Each payroll system you add is another set of these differences to build and maintain.
How do you integrate many payroll APIs at once?
A unified API lets you integrate once and read payroll data from many payroll systems through one data model and one authorization flow. Unified.to has no separate payroll API: payroll objects are part of its HR & Directory API, which covers 683 integrations.
As of 19 October 2026, on supported integrations:
- Payslips (read only): ADP Workforce Now, Paychex, Paylocity, Remote.com and Rippling, among others.
- Pay runs (read only): Check, Deel, Employment Hero Payroll, Paychex, Paycor, Remote.com and Rippling.
- Earnings (read and write): ADP Workforce Now, Paychex, Paycor, Remote.com and Workday, among others.
Check, Paychex, Paycor, Paylocity and Rippling are in beta on Unified.to.
Reads go to the payroll system at request time, with no customer records at rest; connection credentials and operational metadata are encrypted at rest. Payslip changes arrive as webhook events on supported integrations such as Paychex, Paylocity, Remote.com and Rippling; pay runs and pay codes send no change events. For how the payroll objects fit together, see What Is Payroll Integration?; the HR & Directory API overview lists every object, and the integration matrix shows what each integration supports.