Void a Transaction
Use void (reversal) to cancel a transaction before it settles. The transaction is removed from the batch as if it never happened.
When to Use
- Customer changes their mind immediately after payment
- Incorrect amount was charged
- Transaction needs to be cancelled before end of day
Prerequisites
- Understand EPOS communication
- The original transaction's UTI. The UTI is an alphanumeric string consisting of 1-64 characters. Special characters are not allowed. For example, 000000000001, 000000000002, 000000000003. Each UTI must be a unique value. The UTI can be re-used only when the previous one expires, which currently happens after 3 months, though this is subject to change.
- Transaction must be unsettled (same day, before settlement time)
- A valid auth token
Steps
- Send a reversal request with the original transaction's UTI:
curl --location 'https://{IP}:{PORT}/payntpos/1.0.0/transaction?tid={TID}&disablePrinting=false' \
--header 'Content-Type: application/json' \
--header 'Authorization: {AUTH_TOKEN}' \
--data '{
"transType": "REVERSAL",
"reference": "void-123",
"uti": "0f488bbd-f0d8-3cf5-b800-dd3152f7de30"
}'
- The response returns a new UTI for the reversal:
{
"transType": "REVERSAL",
"uti": "1605d7e6-e0e1-33db-9090-2fbb85debbbd"
}
- The original transaction is cancelled.
Request Parameters
| Field | Type | Required | Description |
|---|---|---|---|
| transType | string | Yes | Set to REVERSAL |
| uti | string | Yes | UTI of the transaction to void. The UTI is an alphanumeric string consisting of 1-64 characters. Special characters are not allowed. For example, 000000000001, 000000000002, 000000000003. Each UTI must be a unique value. The UTI can be re-used only when the previous one expires, which currently happens after 3 months, though this is subject to change. |
| reference | string | No | Your reference ID for tracking. The reference ID is an alphanumeric string consisting of 1-36 characters, Special characters are not allowed. Usually shown in 5 groups separated by hyphens, for example, gr3d4fae-9dec-11d0-a763-00a0c91e6bf1. |
Settlement Times
Reversals only work on unsettled transactions. Settlement occurs daily at:
| Season | Settlement Time |
|---|---|
| Winter (GMT) | 01:00 UK time |
| Summer (BST) | 02:00 UK time |
After settlement, use a refund instead.
What Can Be Voided
| Transaction Type | Can Void? |
|---|---|
| Sale (unsettled) | Yes |
| Pre-authorization | Yes |
| Sale (settled) | No – use refund |
| Refund | No |
Important Notes
- Voids do not require the customer's card.
- The void happens instantly—no waiting for the customer.
- If you're unsure whether a transaction has settled, try the void first. If it fails, use a refund.
Related
- How to Process a Refund – For settled transactions
- How to Process a Sale – Original sale transaction