---
title: "Tax registration number"
description: "TRN meaning: the tax registration number a tax authority issues to a VAT-registered business. See how UAE TRNs and Saudi VAT numbers look and where they appear."
url: https://1flux.ai/glossary/tax-registration-number
last_updated: 2026-10-10
---

[Sales and CRM](https://1flux.ai/glossary#sales-and-crm)

# Tax registration number

TRN meaning: the number that identifies a business for VAT, and why it has to be right on every tax invoice.

Glossary Updated 10 October 2026

Definition

A tax registration number (TRN) is the unique number a tax authority issues to a business registered for VAT, which must appear on its tax invoices.

## TRN meaning in the UAE and Saudi Arabia

TRN is a regional term. In the UAE, the Federal Tax Authority (FTA) issues a 15-digit TRN that identifies the business for VAT; businesses registered for corporate tax also receive a corporate tax TRN. In Saudi Arabia, ZATCA issues a 15-digit VAT registration number. Other countries use their own names, such as VAT number, or GSTIN in India.

Buyers check the supplier’s number before claiming input VAT, so a missing or wrong number on a [tax invoice](https://1flux.ai/glossary/tax-invoice) can block recovery.

Example (fictional): a UAE supplier prints TRN 100000000000003 on every tax invoice.

A TRN isn’t a trade licence or [commercial registration](https://1flux.ai/glossary/commercial-registration) number, which come from licensing authorities rather than the tax authority.

In 1flux

Legal entities store the UAE VAT TRN and corporate tax TRN, or the Saudi VAT number, and suppliers store their VAT TRN or VAT registration number. [See ERP for the UAE](https://1flux.ai/solutions/uae)

Related

## Keep exploring

### [VAT](https://1flux.ai/glossary/vat)

A tax charged on sales and reclaimed on purchases.

### [Commercial registration](https://1flux.ai/glossary/commercial-registration)

The record that registers a business to trade in Saudi Arabia.

### [Tax invoice](https://1flux.ai/glossary/tax-invoice)

The invoice a VAT-registered supplier issues for a taxable sale.

### [ERP for the UAE](https://1flux.ai/solutions/uae)

A UAE company set up properly: 5% VAT, TRNs, trade licence, LPOs, GRNs and e-invoicing.

Last updated 10 October 2026