Lead’s Checks capabilities let you offer two primary check flows to your end-users: depositing checks and writing checks. Both flows use the X9 file standard — an electronic check format that includes front and back check images along with structured payment data — and route through the Federal Reserve (Fed).Documentation Index
Fetch the complete documentation index at: https://docs.lead.bank/llms.txt
Use this file to discover all available pages before exploring further.
Lead processes all checks via X9 files. There is no API-based check submission.
Key Terminology
The table below defines the core terms used throughout these guides.| Term | Definition |
|---|---|
| Write a Check | A customer writes a check and gives it to a recipient. The recipient deposits it at their bank, which submits it to the Fed. Lead receives the X9 file from the Fed and debits the customer account. |
| Deposit a Check | A customer deposits a check via your app. You send Lead an X9 file; Lead submits it to the Fed and credits the customer account. |
| X9 File | The standard electronic check file format. Each file contains check images (front and back) plus structured data: amount, check number, account number, and routing number. |
| Incoming X9 | An X9 file Lead receives from the Fed. Used in the Write a Check flow — results in a debit to the customer account. |
| Outgoing X9 | An X9 file Lead sends to the Fed. Used in the Deposit a Check flow — results in a credit to the customer account. |
| Settlement Date | The date the Fed finalizes the funds movement for a given check file. |
| Return | A check rejected after initial processing. For example, because the account is closed or fraud is suspected. Returns travel back via X9 files. |
| MICR Line | Magnetic Ink Character Recognition. The printed line at the bottom of a check containing the routing number, account number, and check number. |
| Remote Deposit Capture (RDC) | The process of depositing a check by photographing it in a mobile app rather than visiting a branch. |
Write a Check Flow
The Write a Check flow begins when your customer writes a check and gives it to a recipient. The recipient deposits it at another financial institution, which submits the check to the Fed. The Fed delivers it to Lead as an incoming X9 file.NoteLead does not provide check printing services. Partners are expected to use their own check printing vendor.
Returns
A return occurs when you determine that an incoming check must not be honored. To return a check, submit an outgoing X9 file containing the return entries. This follows the same path as the Deposit a Check flow. Common return reasons include:- Check details do not match the outstanding check registry
- Check has already been redeemed (duplicate presentment)
- Suspected fraud
- Account closed or insufficient funds
- Correct the check details and post to the customer account
- Make a balance adjustment on the customer account
- Submit an X9 return file to Lead (standard return)
- Initiate a late check return by contacting Lead directly
Deposit a Check Flow
The Deposit a Check flow begins when your customer deposits a check — typically by photographing it in your mobile app using Remote Deposit Capture (RDC). You send Lead an X9 file, Lead submits it to the Fed, and Lead credits funds to your customer.Validation and Fraud Controls
Lead acts as a pass-through in the Deposit a Check flow. You are responsible for all check losses. Build robust pre-submission controls appropriate for your risk appetite before going live.Returns from the Paying Bank
After Lead submits a check to the Fed and the Fed delivers it to the paying bank, the paying bank may return the check — for example, if the account is closed or fraud is detected. There are two ways a return reaches you:- The paying bank submits an X9 return file to the Fed. The Fed routes it to Lead, who forwards it to you via the Write a Check flow.
- The paying bank contacts Lead’s operations team directly, outside of the Fed. Lead’s team opens a case and contacts you as needed.