# BRD-021 — An SSN is not a business registration number

> A Social Security Number must not be submitted in the business registration number field.

- **Rule ID:** BRD-021
- **Layer:** Brand (`BRAND`)
- **Checks:** `brand.ein`
- **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, AWS
- **Applies:** Applies to every 10DLC registration.
- **Canonical URL:** https://ekas.io/rules/10dlc/brand/brd-021/

## Why this rule exists

A sole proprietor with no EIN reaches for the number they do have, and the field accepts nine digits without complaint. It fails verification — an SSN is not in any business register — and in the meantime a government identifier has been sent to a registry that had no business receiving it. The correct route for that user is the sole-proprietor tier, which asks for no tax ID at all.

## How to fix it

Remove the SSN. If the business has an EIN, use it; if it does not, register on the sole-proprietor tier, which verifies by mobile OTP instead. Done when the field holds an EIN or is empty on a sole-proprietor brand.

## Example of a compliant value

```text
ein: 12-3456789 (an EIN) — never 123-45-6789 (an SSN)
```

## Common mistakes

- Applying for an EIN is free and takes minutes on the IRS site, so the sole-proprietor tier is a choice rather than the only option — but it is the right one below the volume threshold.