The UEN on your invoices: what ACRA requires

Every entity registered in Singapore has a Unique Entity Number (UEN) — one number for dealing with ACRA, IRAS and other agencies. It also has to be on your invoices.

The free Singapore invoice generator asks every business type for its UEN and prints it under your name.

Who must show it

• Companies — Companies Act 1967, section 144: a company's name and registration number (its UEN) must appear on its invoices, letters and other business documents.
• Sole proprietorships and partnerships — the Business Names Registration Act 2014 and its regulations: a registered business shows its registration number (its UEN) on invoices and similar documents.
• LLPs — the Limited Liability Partnerships Act requires their name and registration number too.

In practice: if you have a UEN, put it on every invoice, whether or not you're registered for GST.

The three formats

The last character is a check letter. ACRA doesn't publish how it's calculated, so a UEN can only be fully confirmed by searching it on Bizfile or uen.gov.sg. The UEN checker checks the format.

UEN and GST registration number

When a business registers for GST, IRAS usually uses its UEN as the GST registration number. Some businesses, especially older or overseas ones, have an M-series GST number instead, like M90312345X. On a tax invoice, show your GST registration number with that label, and your UEN as well — Invoice Native prints "GST Reg. No. 201828446N · UEN 201828446N".

A worked example

Merlion Studio Pte. Ltd. (UEN 201828446N) is registered for GST under its UEN. Its tax invoices show, under its name: "GST Reg. No. 201828446N · UEN 201828446N". Its founder's side business, Tan Design, is a sole proprietorship that isn't GST-registered: its invoices show "UEN 52912345A" and no GST number.

Freelancers without a UEN

If you work under your own full name and haven't registered a business, you may not have a UEN; your invoices then show your name and contact details. Once you trade under a business name, you must register it with ACRA, and you get a UEN.

UEN on other documents

The same rules reach beyond invoices. Your UEN should also be on:

• quotations and estimates sent under your business name;
• credit notes and receipts;
• business letters, order forms and your website, for companies under section 144.

Invoice Native prints the UEN on every document it makes — invoices, quotes, credit notes and receipts — so you don't have to remember.

Common mistakes

• Printing an NRIC instead. Use your UEN; never put an NRIC on an invoice.
• An old UEN after restructuring. A sole proprietorship that becomes a company gets a new UEN — update your invoices from the company's start date.
• Mixing up the GST number. If IRAS gave you an M-series GST number, don't print your UEN as the GST number.
• Typos. One wrong digit can still look like a valid UEN. Copy it from your ACRA business profile.

Where to find your UEN

Your UEN is on your ACRA business profile and your registration notice. You can also look it up by your business name on uen.gov.sg, which lists UENs issued by ACRA and other agencies. If you can't find it, check the email from ACRA when you registered, or log in to Bizfile.

Quotes and contracts with other businesses

Large customers, especially government agencies and listed companies, often add your UEN to their vendor records and match it against your invoices. Using the same UEN on your quote, contract and every invoice avoids payment delays. If you change your business structure, tell your customers your new UEN before you invoice under it.

Getting it right in Invoice Native

Invoice Native requires a UEN from every Singapore business type — sole proprietorship, partnership, LLP and company — and checks its format before you download or issue anything. It never asks for or prints your NRIC.