# 21728: Campaign registration failed due to length validation failures

Log Type: APPLICATION

Log Level: ERROR

## Description

This error appears when your US A2P 10DLC Campaign registration includes one or more fields that do not meet the documented length requirements for campaign creation. Common fields with length limits include `description`, `messageFlow`, each entry in `messageSamples`, and optional keyword-response fields such as `optInMessage`, `optOutMessage`, and `helpMessage`.

### Possible causes

* The `description` value is shorter than 40 characters or longer than 4096 characters.
* The `messageFlow` value is shorter than 40 characters or longer than the allowed maximum for the Campaign API.
* You provided fewer than two `messageSamples`, more than five `messageSamples`, or one of the samples is shorter than 20 characters or longer than 1024 characters.
* An optional field you supplied exceeds its limit, such as `optInMessage`, `optOutMessage`, or `helpMessage` at 20 to 320 characters, or `optInKeywords`, `optOutKeywords`, or `helpKeywords` over 255 characters.
* The text you submitted is too short to satisfy the field requirements. For example, `description` must explain who is sending messages, who receives them, and why messages are being sent, and `messageFlow` must explain how end users opt in.

### Possible solutions

* Review every text field in your Campaign submission and update any value that is outside the documented length limits before you resubmit.
* Update `description` so it clearly explains who the sender is, who the recipients are, and why messages are being sent. Keep the value within the allowed length range.
* Update `messageFlow` so it fully describes every opt-in path you use. If you collect consent in more than one way, list all methods in the same field and keep the value within the documented limit.
* Provide two to five realistic `messageSamples` that match the selected use case. Keep each sample within the allowed length range, include the Brand name or website in each message, and use square brackets `[]` for variable content.
* If you manage keyword-based opt-in, opt-out, or help flows yourself, make sure the related messages and keyword lists are included when required and fit their documented length limits.
* If you are correcting a rejected Campaign in Console, update the Campaign description, sample messages, and consent details in the resubmission form, then retry review.

#### Additional resources

* [A2P 10DLC - Gather the Required Business Information](/docs/messaging/compliance/a2p-10dlc/collect-business-info)
* [UsAppToPerson Resource](/docs/messaging/api/usapptoperson-resource)
* [Troubleshooting and rectifying A2P Campaigns](/docs/messaging/compliance/a2p-10dlc/troubleshooting-a2p-brands/troubleshooting-and-rectifying-a2p-campaigns)