The Payment Module API enables automated creation, execution, scheduling, and monitoring of payments for new or existing transaction agreements.

It supports both Biz Core–managed payment schedules and partner-managed (just-in-time) execution, allowing integrators to choose the model that best fits their platform and operational requirements.

High-level Integration Flow

1. Create a transaction agreement (without source)
2. Schedule transactions immediately after agreement creation (Optional- Biz Core–managed schedule only)
3. Customer provides payment method details
4. Customer signs the agreement
5. Payments are executed on schedule (Biz Core–managed schedule) or ad-hoc (Partner-managed schedule)
6. Transaction status is tracked
7. Late rejections are monitored (direct debit only)

⚠️

Direct debit transactions can be reversed after completion by the financial institution.

You must monitor for late rejections for at least 7 days after execution.

What the Payments Module Supports

• Creation of transaction agreements between customers and merchants

• Secure capture and update of payment sources (bank account/card)

• Scheduling of once-off and recurring transactions within agreements

• Ad-hoc execution of transactions without scheduling

• Transaction status synchronisation via:

  • API polling (pull)
  • Webhooks (push)

• Deferred outcome handling (clearing, disputes, late rejections)

Scheduling Strategy (Important Design Decision)

You can integrate in one of two ways. This choice directly affects how the agreement appears in Biz Core.

Option 1 — Biz Core–managed schedule

• All scheduled transactions are created immediately after agreement creation

• The agreement in Biz Core shows:

  • Full payment schedule
  • Recurring transaction definitions
  • Individual scheduled payments

Recommended when:

• Payment plans are fixed at agreement creation
• You want Biz Core to fully represent the repayment schedule

Option 2 — Partner-managed schedule

• Your platform manages the schedule internally

• Biz Core only reflects:

  • The agreement terms with your merchant
  • Executed transactions

• No scheduled transactions appear on the agreement

Why most partners choose this:

• Customers frequently change payment frequency or dates
• Catch-up and additional payments are common
• Declines and retries require custom logic
• Eliminates ongoing resync of scheduled transactions

Integration Guide

Step 1 — Create a Transaction Agreement (Without Source)

Create the agreement and customer record. This returns identifiers and a Source Creation URL for collecting payment details.

Outcome:

• Agreement created
• Customer created or associated
• Agreement identifiers stored in your platform
• Source Creation URL generated

Step 2 — (Biz Core–managed Only) Schedule Transactions

⚠️

If you are using a partner-managed schedule, skip this step.

If you want Biz Core to manage the payment schedule, schedule all payments immediately after creating the agreement.

Important:

• Scheduled transactions will appear on the agreement
• Recurring schedules generate individual future transactions
• These schedule transactions details become visible on the DDA document and on the agreement page on Biz Core portal.

Step 3 — Customer Provides Payment Method Details

Present the Source Creation URL retrieved in the response from Step 1 to the customer:

• Redirect
• Iframe embed
• Secure link

Biz Core securely collects and stores the payment method.

ℹ️

When a customer chooses to make payments by card, a separate Direct Debit Authority (DDA) signing process is not required.

Step 4 — Customer Signs the Agreement (Direct Debit only)

Once the bank account payment method is provided, the customer is automatically redirected to a signing page to sign(authorise) the agreement.

After signing:

• The agreement becomes fully authorised
• Scheduled transactions (if any) are locked in
• Payments can now be executed

Step 5 — Execute Payments

Option A — Biz Core–managed schedule

Payments are automatically executed by Biz Core on their scheduled dates.

No additional API calls are required for execution.

Option B — Partner-managed schedule (Ad-hoc execution)

Execute payments on demand based on your internal schedule.

Step 6 — Track Transaction Status

Track progress and outcomes using polling:

OR Webhooks:

Step 7 — Monitor Late Rejections (Direct Debit Only)

Even after a transaction is marked Complete, it may later be reversed.

Best practice:

• Check daily
• Monitor for at least 7 days after execution

Agreement Representation in Biz Core (Summary)

Additional Endpoints

These endpoints support secondary workflows such as agreement signing, payment source updates, and scheduled transaction maintenance. They are not required for the basic happy-path integration but are commonly used in production.

Get Transaction Agreement Correlation

Returns correlation information for transaction agreements based on the supplied filter criteria. This is typically used to reconcile agreements between your platform and Biz Core or to locate agreements using external references.

Send Transaction Agreement for Signature

Used to send the customer the authorisation documents for signing (typically required for direct debit agreements).

Update Agreement Source (Direct Debit)

Updates the bank account details for an existing transaction agreement via API.

Retrieve Source Creation URL (Customer-Driven Update)

Retrieves a hosted Source Creation URL that allows the customer to update their payment method securely.

Final Notes

• Choose your scheduling strategy before going live
• Switching strategies mid-agreement requires cleanup of scheduled transactions
• Webhooks are strongly recommended for production integrations