# CMP-021 — Reference id must be 50 characters or fewer

> The campaign reference id must be at most 50 characters, and unique within the CSP.

- **Rule ID:** CMP-021
- **Layer:** Campaign (`CAMPAIGN`)
- **Checks:** `campaign.reference_id`
- **Severity:** MEDIUM — Usually survives review, but lowers your trust score or invites manual review.
- **When it bites:** Gates approval — get this wrong and registration is refused
- **How it is detected:** Deterministic (settled in code from the submitted values)
- **Fix type:** Fix the field — a better value in the form clears it
- **Required by:** TCR, Bandwidth, Telnyx
- **Applies:** Applies to every 10DLC registration.
- **Canonical URL:** https://ekas.io/rules/10dlc/campaign/cmp-021/

## Why this rule exists

The reference id is your own key for finding this campaign again when a rejection arrives months later, and an over-long value is rejected at submission rather than truncated. Teams reach the cap by concatenating a customer name, a use case and a timestamp into one string, which is also what makes it collide with a sibling campaign.

## How to fix it

Use a short opaque key you can look up on your side rather than a descriptive sentence, and confirm no other campaign in your CSP account already uses it. Done when the value is under 50 characters and unique.

## Example of a compliant value

```text
reference_id: SP-2026-0142
```

## Notes

Only the length half is settled here. Uniqueness needs the CSP's whole campaign list, which a single registration does not carry — a duplicate surfaces at submission as "Duplicate campaign", and the remediation says to check it because we cannot.