> ## Documentation Index
> Fetch the complete documentation index at: https://docs.dintero.com/llms.txt
> Use this file to discover all available pages before exploring further.

<AgentInstructions>

## Submitting Feedback

If you encounter incorrect, outdated, or confusing documentation on this page, submit feedback:

POST https://docs.dintero.com/feedback

```json
{
  "path": "/docs/checkout/tokenization-error-handling",
  "feedback": "Description of the issue"
}
```

Only submit feedback when you have something specific and actionable to report.

</AgentInstructions>

# Tokenization error handling

> Handle Dintero card-token errors such as Visa and Mastercard "do not try again" responses and excessive reattempts when running merchant-initiated payments.

### Do Not Try Again & Excessive Reattempts

In accordance with directives from Visa and Mastercard there are
2 different types of limitations in the amount of successive reattempts
of previously failed transaction using `unscheduled_purchase` or `recurring_purchase`

One such limitation will be limiting the amount of successive reattempts of a
previously failed transaction that can be done using creditcard based payment
method within a specified period The limitation in question varies based on the
card brand:

* MasterCard - 10 failed payment attempts allowed during a period of **24 hours**.
* Visa - 15 failed payment attempts allowed during a period of **30 days**.

> Note that all of the attempts has to get a failed response to be added to the
> limit quota - if a transaction goes through successfully, the quota will reset.

The other limitation is in the case that Visa or Mastercard gives such a
response that is flagged as “Do Not Retry” in accordance to Visa and MasterCard
regulations. This response is given in the cases that they deem the transaction
to never be possible to be valid - as an example, if the card no longer exists,
and thus there is no point in retrying.

In these cases, the card will be blocked immediately and no further attempts
are allowed.

Both of these limitations are based on the combination of the acquiring
agreement that the transaction was initiated from, and the PAN of the card
that was used. That is, a card might be blocked because of
"Excessive Reattempts" at a particular merchant, while being allowed more
reattempts at another. Please note that in the case a new card is issued in
place of an old expired one, the new card usually keeps the same PAN - meaning
that if the old card was blocked, the new one will be as well (until the period
resets). This marks the importance of having such a logic in place that limits
reattempts before the block actually takes place - this is where the new,
clearer response messages will help.

<Info>
  Merchant is resposible for managing their retry policy for payments that
  fails, and not retry when payment fails with `DO_NOT_RETRY` error.
  Insufficient error handling will cause cards to be **blocked**
</Info>

#### `payex.creditcard` authorization error example

A 200 response will be returned if the pay request fail because of
authorization error. The transaction will have status **FAILED** and more
information about the cause can be found in the **AUTHORIZE** event

```json theme={null}
{
  "id": "...",
  "status": "FAILED",
  "events": [
    {
      "event": "INITIALIZE",
      "success": true
    },
    {
      "event": "AUTHORIZE",
      "success": false,
      "error": {
        "type": "REJECTED_BY_ACQUIRER_POSSIBLE_FRAUD",
        "code": "payex:errorCode:REJECTED_BY_ACQUIRER_POSSIBLE_FRAUD",
        "message": "payex:errorDescription:Wrong card-no check digit response-code: 34",
        "result_code": "34"
      }
    }
  ]
}
```

### Prevent duplicate transactions

Use the `Dintero-Feature-Toggles` header to prevent creating duplicate
transactions.

Including `strict-merchant-reference` value in the header will prevent creating
duplicate transaction as it will require the `merchant_reference` to be **unique**
within 24 hours

**headers**

```
Dintero-Feature-Toggles: strict-merchant-reference
Content-Type: application/json
```

**body**

```json theme={null}
{
  "session": {
    "url": {
      "callback_url": "https://example.com/callback?method=GET"
    },
    "customer": {
      "tokens": {
        "payex.creditcard": {
          "payment_token": "<token previously acquired>"
        }
      }
    },
    "order": {
      "amount": 29990,
      "currency": "NOK",
      "vat_amount": 6000,
      "merchant_reference": "order-1"
    },
    "configuration": {}
  },
  "payment": {
    "payment_product_type": "payex.creditcard",
    "operation": "unscheduled_purchase"
  }
}
```

A 400 response will be returned if `merchant_reference` was duplicated

```json theme={null}
{
    "session_id": "T11223445.5cyWnV68vzJ1kYjZPrKWWm",
    "error": {
        "message": "session.order.merchant_reference",
        "code": "DUPLICATE"
	}
}
```