# BRD-026 — An alternate identifier needs its type alongside it

> Where altBusinessId is supplied, altBusinessIdType must be one of DUNS, GIIN, LEI or NONE.

- **Rule ID:** BRD-026
- **Layer:** Brand (`BRAND`)
- **Checks:** `brand.alt_business_id + brand.alt_business_id_type`
- **Severity:** LOW — Best practice. Worth fixing, rarely fatal on its own.
- **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 to every 10DLC registration.
- **Canonical URL:** https://ekas.io/rules/10dlc/brand/brd-026/

## Why this rule exists

The alternate identifier is optional and strengthens verification when it is present, but a number with no type is a number nobody can look up — the registry rejects the pair rather than storing half of it. It usually happens when a DUNS number is added helpfully, from a procurement record that never carried a type field.

## How to fix it

Set altBusinessIdType to the register the alternate number came from — DUNS for Dun & Bradstreet, GIIN for the IRS FATCA register, LEI for a legal entity identifier. If you do not have one, clear both fields rather than sending a bare number. Done when either both fields are populated or neither is.

## Example of a compliant value

```text
alt_business_id: 123456789 · alt_business_id_type: DUNS
```

## Provider rejection codes

| Provider | Code | Resubmission allowed |
| --- | --- | --- |
| TCR | `501` | yes |

## Notes

The field is optional and validated only when present, which is why this is LOW rather than BLOCKING — but it will reject the whole brand submission, so it costs a round trip like any other field error.