# XBC-008 — A sole proprietor gets one campaign and one number

> A SOLE_PROPRIETOR brand may hold exactly one campaign, and that campaign exactly one telephone number.

- **Rule ID:** XBC-008
- **Layer:** Brand ↔ campaign (`CROSS`)
- **Checks:** `brand.entity_type + campaign count + campaign.number_pool`
- **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, T-Mobile, Twilio
- **Applies:** Applies when the brand is a sole proprietor.
- **Depends on:** XBC-001
- **Canonical URL:** https://ekas.io/rules/10dlc/cross/xbc-008/

## Why this rule exists

The sole proprietor tier is a low-volume path for individuals with no EIN, and the single-campaign, single-number limit is what the carriers accept in exchange for the reduced vetting. A second campaign is refused rather than queued, so somebody who registers a marketing campaign beside their appointment reminders loses the fee and the time. Pooling is the same limit stated the other way: there is only ever one number to pool.

## How to fix it

Fold everything the programme sends into the one sole-proprietor campaign, on one number, and turn number pooling off. If the business genuinely needs a second campaign or more throughput, obtain an EIN and re-register as a standard entity — the tier is the limit, not the campaign.

## Example of a compliant value

```text
Sole proprietor: 1 campaign · 1 phone number · numberPool: false
```

## Common mistakes

- Registering the second campaign under a second sole-proprietor brand does not work either: the tier caps the mobile number behind the brands as well, so the same person cannot hold an unlimited number of them.