# XBC-005 — Sole proprietor brand and campaign both require a reference ID

> referenceId is mandatory — not optional — on both the brand and the campaign for the sole proprietor tier.

- **Rule ID:** XBC-005
- **Layer:** Brand ↔ campaign (`CROSS`)
- **Checks:** `brand.reference_id + campaign.reference_id`
- **Severity:** BLOCKING — Breaking this rule gets the submission rejected outright.
- **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
- **Applies:** Applies when the brand is a sole proprietor.
- **Canonical URL:** https://ekas.io/rules/10dlc/cross/xbc-005/

## Why this rule exists

The reference ID is how the sole proprietor tier ties a brand and campaign to the verified mobile number behind them, which is the only identity check that tier has. It is optional everywhere else, so integrations built against the standard flow omit it and fail here.

## How to fix it

Populate referenceId on both the brand and the campaign with your own stable identifier for this customer.

## Example of a compliant value

```text
referenceId: acme-sp-2026-0041
```

## Notes

Catalog BRD-077 / CMP-022.