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

# Card Validation Errors

> Error codes returned when card entry validation fails. Invalid number, expiration, CVV, and Luhn check failures.

When card data is submitted to PCI Booking (via a [hosted card entry form](/capture-cards/hosted-card-entry-form), [Card By Link](/capture-cards/card-by-link), or API), the data is validated before tokenization. If validation fails, one of the following error messages is returned.

## Card Number Errors

| Error                                | Description                                                                       |
| ------------------------------------ | --------------------------------------------------------------------------------- |
| Number is longer than 22 chars       | Card number exceeds maximum length                                                |
| Invalid character at position        | Non-numeric character found in card number                                        |
| Invalid separator                    | Unrecognized separator character between digit groups                             |
| Number has less than 12 digits       | Card number too short                                                             |
| Luhn (Mod10) error                   | Card number fails the Luhn checksum algorithm                                     |
| Too many separator characters        | Excess separators in card number                                                  |
| Invalid number                       | Card number is not valid                                                          |
| Card number does not match card type | The entered number does not match the selected card type (card capture form only) |

## Expiration Date Errors

| Error                   | Description                        |
| ----------------------- | ---------------------------------- |
| Month should be 1 to 12 | Month value is out of range        |
| Expired card            | The expiration date is in the past |

## CVV Errors

| Error                     | Description                                                 |
| ------------------------- | ----------------------------------------------------------- |
| CVV must be 3 or 4 digits | CVV length is invalid (3 digits for most cards, 4 for AMEX) |

## Issue Number Errors

| Error                             | Description                               |
| --------------------------------- | ----------------------------------------- |
| Issue number should be "1" or "2" | Issue number is outside the allowed range |

## Cardholder Name Rules

The cardholder name field accepts:

* Maximum **32 characters**
* Alphanumeric characters (A-Z, a-z, 0-9)
* Special characters: `'` `-` `.` `!` `£` `$` `%` `^` `*` and space

## Related

* [Hosted Card Entry Form](/capture-cards/hosted-card-entry-form) - Set up the card capture form that triggers these validations
* [Request Card Entry Form API](/api-reference/tokenize-cards/request-card-entry-form) - API reference for generating the card entry form