Overview

Instant RTP Diagram

sequenceDiagram
    participant LMS as Merchant/LMS
    participant API as FLEX API / CORE
    participant RTP as RTP Network
    participant Bank as Bank

critical Verification
    LMS->>API: 1. Request Token
    API->>LMS: 2. Token Verified + Sent Back
    end

    LMS->>API: 3. Post Instant RTP Transaction
    API->>API: 4. Validate + Check limits
    API->>RTP: 5. Submit transaction
    RTP->>Bank: 6. Settle payment instantly
    RTP-->>API: 7. Settlement confirmation
    API-->>LMS: 8. Response (status = settled or failed)

InstantRTP Transactions

InstantRTP lets you disburse funds directly to a recipient’s bank account, usually within seconds. Each transaction is routed through RTP or FedNow rails based on the recipient bank’s network availability.

InstantRTP transactions work well for use cases such as loan funding, refunds, reimbursements, and other time-sensitive payments.

Before You Begin

Before creating an InstantRTP transaction integrators must:

Obtain an access token using the authentication documentation.
Confirm that the InstantRTP subscription is active using the Instant RTP subscription page on the Flex Portal.
Ensure that your processing account has available funds.
Know your per transaction and daily limits, these values can be found on the Instant RTP subscription page on the Flex Portal.

Transaction Workflow

Step 1: Check the Routing Number

Gather the recipient’s routing number, and use the below endpoint to check whether their financial institution can receive an instant credit:

GET /api/v3/InstantRtpRoutes/{routingNumber}

See the route check documentation for a more detailed endpoint description.

Step 2: Create the Transaction

Create an InstantRTP transaction using your assigned company code:

POST /api/v3/InstantRtpTransactions/companycode/{companyCode}

See the creating transactions documentation for a more detailed endpoint description.

Step 3: Monitor the Transaction Status

If the status in the response from Step 2 is pending after the up to 300 second wait, use the below endpoint with a uniqueId to retrieve the current details and status of the transaction:

GET /api/v3/InstantRtpTransactions/companycode/{companyCode}/{uniqueId}

See the getting transactions documentation for a more detailed endpoint description.

Request for Return of Funds

A successful InstantRTP transaction cannot be voided like an unsent ACH transaction. You may submit a request for return, but the request is separate from the original transaction and should not be treated as an immediate cancellation.

See the request for return documentation for further details.