Starling Bank payments API Integration for Payroll App

PayCIS is an online payroll application used by UK businesses to prepare and approve bulk payments to workers.
Website: https://paycis.co.uk

The payroll logic, approvals, logging, and manual payment fallback are already built.
We now want to add automated payments for users with a Starling Business bank account.

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What we need

A developer to integrate Starling Bank’s native Business API so approved payroll payments can be executed directly from the user’s own Starling account, with automatic success/failure updates.

This is:
• ✔ Bank-native API
• ❌ Not Open Banking
• ❌ Not file uploads
• ❌ No client money handling

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Scope

1. Starling account connection
• Implement Starling OAuth (connect / disconnect)
• Secure token storage and refresh
• Reuse existing OAuth patterns where possible

2. Payroll payment execution
• Use Starling Business Payments API
• One API call per payment (10–50 per run)
• Store paymentUid and prevent duplicates

3. Payment status updates
• Handle Starling webhooks
• Mark payments as paid or failed
• Log outcomes and failure reasons

4. Error handling
• Insufficient funds, invalid details, revoked tokens
• Retry or fall back to manual payment

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Deliverables
• Starling OAuth integration
• Payment execution logic
• Webhook handling
• Brief technical notes

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To apply

Please include:
• Relevant bank / payments API experience
• Confirmation this is Starling Business API (not Open Banking)
• Estimated timeline and FIXED cost. Note that we do not accept estimated or open ended costs, only a FIXED price. Please confirm this in your response.