Collections API - Union Bank BaaS

Overview

The Collections API handles money coming in to your platform — the opposite of Payments, which handles money going out. When a customer wants to pay you, you use the Collections API to:

Create a collection reference (a payment link or account number) for the customer.
The customer sends money to that reference from any bank in Nigeria.
The platform credits your virtual account and fires a webhook to notify you instantly.
You query the Collections API to reconcile and confirm the credit.

Collections work over the NIP network, so funds arrive in near real-time.

Base URL

Environment	Base URL
Sandbox	`https://sandbox.api.unionbank.ng`
Production	`https://api.unionbank.ng`

Authentication

Authorization: ApiKey <your-api-key>

How Collections Work

Your platform                  Customer                   NIP Network
     │                             │                            │
     │──POST /collections/intent──▶│                            │
     │◀──collection_reference──────│                            │
     │                             │                            │
     │                             │──Bank transfer────────────▶│
     │                             │                            │──Credits virtual account
     │◀──Webhook notification──────────────────────────────────│
     │                             │                            │
     │──GET /collections/{id}──────────────────────────────────▶│
     │◀──Confirmed credit──────────────────────────────────────│

Endpoints

Create Collection Intent

POST /v1/collections/intent Generate a unique payment reference for a customer to send you money. You can set an exact expected amount (for invoices) or leave it open (for top-ups). What you send:

Field	Type	Required	Description
`destination_account_id`	string	Yes	The virtual account that should receive the funds
`expected_amount`	integer	No	Expected amount in kobo. If set, only this exact amount is accepted
`currency`	string	Yes	Always `NGN`
`description`	string	No	What this payment is for — shown in the webhook and statement
`expires_at`	string	No	ISO 8601 datetime after which this intent expires. Default: never
`customer_ref`	string	No	Your internal reference for the customer (e.g., order ID)
`metadata`	object	No	Any key-value pairs for your own records

What you get back:

Field	Description
`collection_id`	Unique ID for this collection intent
`collection_reference`	A unique string the customer includes in their transfer narration
`destination_account_number`	The NUBAN to send money to
`destination_bank_name`	Always `Union Bank of Nigeria`
`destination_bank_code`	Union Bank’s CBN bank code
`expected_amount`	Amount in kobo (if specified)
`status`	`pending` — waiting for payment
`expires_at`	Expiry datetime or `null`

Example request:

{
  "destination_account_id": "acct_9d7e1c",
  "expected_amount": 150000,
  "currency": "NGN",
  "description": "Payment for Order #ORD-20240115-042",
  "customer_ref": "ORD-20240115-042"
}

Example response:

{
  "collection_id": "col_7b3f1a",
  "collection_reference": "UBN-COL-7B3F1A",
  "destination_account_number": "0123456789",
  "destination_bank_name": "Union Bank of Nigeria",
  "destination_bank_code": "032",
  "expected_amount": 150000,
  "currency": "NGN",
  "status": "pending",
  "expires_at": null,
  "created_at": "2024-01-15T11:00:00+01:00"
}

Show the customer the destination_account_number, destination_bank_code, and collection_reference. Instruct them to include the reference in the transfer narration so the payment is automatically matched to their order.

Get Collection Status

GET /v1/collections/{collection_id} Check whether a payment has been received for a specific collection intent. Status values:

Status	Meaning
`pending`	Awaiting payment from customer
`partially_paid`	Customer sent less than the expected amount
`paid`	Full payment received — virtual account credited
`overpaid`	Customer sent more than expected
`expired`	Intent expired before payment arrived
`cancelled`	Manually cancelled via the API

What you get back:

Field	Description
`collection_id`	Intent identifier
`status`	Current status (see above)
`expected_amount`	Amount expected in kobo
`amount_received`	Amount actually credited in kobo
`payment_reference`	NIP session reference for the inbound transfer
`paid_at`	ISO 8601 timestamp when the credit was received

List Collections

GET /v1/collections Returns all collection intents for your business, with filtering options. Query parameters:

Parameter	Type	Default	Description
`status`	string	all	Filter by status
`destination_account_id`	string	—	Return only collections for this account
`from`	string	—	Start date `YYYY-MM-DD`
`to`	string	—	End date `YYYY-MM-DD`
`page`	integer	`1`	Page number
`per_page`	integer	`20`	Max 100

Cancel Collection Intent

DELETE /v1/collections/{collection_id} Cancel an outstanding collection intent. Once cancelled, any payment arriving with this reference will be rejected and returned to the sender.

Webhooks for Collections

The fastest way to know a payment arrived is via a webhook. When a collection intent is paid, the platform immediately sends a collection.paid event to your webhook URL. Webhook payload example:

{
  "event": "collection.paid",
  "data": {
    "collection_id": "col_7b3f1a",
    "amount_received": 150000,
    "currency": "NGN",
    "payment_reference": "NIP20240115XXXXXX",
    "customer_ref": "ORD-20240115-042",
    "paid_at": "2024-01-15T11:03:47+01:00"
  }
}

See the Webhooks product guide for how to set up your webhook endpoint and verify the signature.

Simulating Payments in Sandbox

In the sandbox environment, incoming payments do not arrive automatically. Use the simulation endpoint to trigger a test credit: POST /v1/collections/{collection_id}/simulate-payment What you send:

Field	Type	Required	Description
`amount`	integer	Yes	Amount to simulate in kobo
`sender_name`	string	No	Name of the simulated sender
`sender_account`	string	No	Simulated sender account number

This triggers the full webhook flow as if a real payment arrived — useful for testing your webhook handler end-to-end.

Error Codes

HTTP Status	Error Code	Meaning
400	`VALIDATION_ERROR`	Missing or invalid fields
404	`COLLECTION_NOT_FOUND`	No collection intent with this ID
409	`COLLECTION_ALREADY_PAID`	Payment already received for this intent
410	`COLLECTION_EXPIRED`	Intent has expired — create a new one
429	`RATE_LIMIT_EXCEEDED`	Too many requests

Full API Reference

Open API Playground

Try Collections endpoints live in the browser

API Reference

​Overview

​Base URL

​Authentication

​How Collections Work

​Endpoints

​Create Collection Intent

​Get Collection Status

​List Collections

​Cancel Collection Intent

​Webhooks for Collections

​Simulating Payments in Sandbox

​Error Codes

​Full API Reference

Open API Playground

Overview

Base URL

Authentication

How Collections Work

Endpoints

Create Collection Intent

Get Collection Status

List Collections

Cancel Collection Intent

Webhooks for Collections

Simulating Payments in Sandbox

Error Codes

Full API Reference