Skip to main content
Welcome to the ACH Technical Guides. This documentation serves as a centralized reference for understanding and integrating with our API. These guides are designed to provide:
  • A high-level overview of each API endpoint
  • Request and response modeling to help guide implementation
  • Best practices and common patterns for working with our platform
These guides are intended for developers, engineers, and technical stakeholders working with the our ACH API.

​
Goals of This Documentation

  • Clarity – Reduce guesswork by providing exact input/output examples
  • Consistency – Encourage standardized usage of endpoints across teams
  • Speed – Enable quicker implementation and onboarding for developers

​
Testing

To test in GrailPay’s sandbox environment you will need to connect to our Sandbox API Environment. You can reach our sandbox environment at: https://api-sandbox.grailpay.com

​
Testing Bank Accounts

When creating people, businesses, or merchants in the sandbox, you can simulate bank accounts using:
  • A random 12-digit account number
  • One of the following test routing numbers:
    • 226078036
    • 221979363
This setup allows you to test your full integration flow — including onboarding, transactions, and ACH processing — without interacting with real financial institutions. interacting with real financial institutions.

​
Testing Social Security Numbers (SSNs)

When testing in the Sandbox environment, Social Security Numbers (SSNs) must follow specific formatting rules to be considered valid. The SSN:
  • Cannot begin with "000" or any value in the range "900–999"
  • Cannot have "00" as the middle two digits
  • Cannot end in "0000"
Any other valid 9-digit SSN format outside of these constraints is acceptable for testing purposes.
These guides are a work in progress. If you don’t see what you need, please reach out to our support team for assistance.
⌘I