Applying for a Special UEN (SUN) in Singapore: Tiers, Fees and the One-Shot Timing Trap

A Special UEN is a memorable entity number you pay extra for at the point of registration. It comes in two priced tiers, you choose it from a published list of what is still available, and you can only buy one while you are registering a new entity. Miss that moment and the door closes.

Raffles Corporate Services works with a panel of experienced Singapore law firms who offer cost-effective and efficient legal service and advice. This article is general information only and is not legal advice.

That last point is the whole article. Every Singapore business gets a Unique Entity Number for free when it registers. The number is allocated to you, and for most companies it is a forgettable string that nobody, including the finance team, can recite from memory. A Special UEN, or SUN, is the paid alternative: you pick a pattern you can actually remember, or one that carries the digits your customers respond to.

What trips people up is not the fee. It is that the option appears once, at the payment stage of registration, and there is no route back to it afterwards.

What a UEN is, and what part of it you can choose

Your UEN is the single identifier that government agencies, banks, insurers and counterparties use to identify your entity. It appears on your Bizfile records, your invoices, your CPF and IRAS dealings, and every tender document you will ever submit.

The format varies by entity type, and that matters because it determines which digits are yours to choose. From the patterns ACRA publishes, the shape works like this:

The prefix and the trailing check letter are generated by the system. You never get to choose those. A company registered in 2026 will always have a UEN beginning 2026, and no fee changes that.

So when you buy a SUN, you are buying a specific digit block, from a list of blocks that have not yet been taken.

The two tiers and what each one costs

ACRA prices SUNs in two tiers, and the tier depends entirely on the pattern, not on the entity type.

The pricing logic is not arbitrary. The digit 8 is culturally loaded in Singapore and the region, and ACRA has priced accordingly. Any block containing an 8, however it is arranged, sits in the higher tier. A block of repeating digits that avoids 8 entirely, or one that simply ends in a triple, sits in the lower tier.

Two practical consequences follow.

First, if your budget is $1,000 rather than $3,000, you are shopping in the tier two list, and you should accept now that you will not get an 8. Deciding this before you open Bizfile saves a frustrating half hour.

Second, the fee is per registration, not per year. There is no annual renewal on a SUN. You buy the number once and it stays with the entity for its life.

When you can apply, and why timing is everything

You can apply for a SUN only when you are registering a new business entity. The choice is offered at the payment stage of the registration transaction, alongside the registration fee itself.

If your entity is already registered, you cannot buy a SUN for it. Not by paying more, not by applying separately, not by filing a notice. The number you were allocated is the number you have.

There is one family of exceptions worth knowing, because it is genuinely useful: certain conversion transactions create a new registration and therefore reopen the SUN window. Converting an existing firm or partnership into an LLP is one, and converting an existing entity into an accounting LLP is another. In both cases a new entity number is issued, so the SUN option appears again.

The steps, in order

1. Decide your budget and therefore your tier, before you start the registration.
2. Browse the list of available SUNs published on Bizfile and shortlist three or four blocks, not one. Availability changes.
3. Complete your name application and the registration transaction as normal. Our guide to what Bizfile actually is and what you can do in it covers the mechanics if this is your first time in the system.
4. At the payment stage, select the option to choose a SUN rather than accept the system-allocated UEN.
5. Pick your block from the available list and pay the registration fee plus the SUN fee together.
6. Confirm the UEN that appears on your registration outcome matches the block you selected, before you print anything.

What goes wrong, and what it costs

The number is non-refundable and non-exchangeable. This is the expensive one. If you pay $3,000 for a block and then decide you preferred a different one, or you realise you misread a digit, there is no exchange mechanism and no refund. The money is spent. Read the block aloud twice before you confirm.

The shortlist of one. SUN availability is live. The block you picked from the list on Tuesday may be gone by Thursday, and if you have anchored your branding to it you will be in a bad mood at the payment stage. Shortlist several.

Assuming the SUN follows a name change. It does not, and it does not need to. A SUN attaches to the entity number, not the trading name. You can change your company name as often as you like and the UEN stays put. People sometimes worry about this the wrong way round.

Assuming the SUN follows a restructuring. It does not. If you convert your sole proprietorship into a private limited company, that is a new entity with a new UEN, and your old number does not travel with it. If you are thinking about that route, read our guide on converting a sole proprietorship to a Pte Ltd before you buy a SUN for the sole proprietorship. Buying a premium number for a vehicle you intend to retire in eighteen months is money set on fire.

Buying the number and then not using it. A SUN is only worth the fee if the number actually reaches the people who deal with you: invoices, quotations, tender submissions, your website footer. Companies buy a memorable number and then never put it anywhere a customer can see it. If the plan is purely internal convenience, the free UEN does the same job for nothing.

Is a SUN worth it?

Honestly, for most SMEs, no. The free UEN performs every regulatory function a SUN performs. Nobody at IRAS, ACRA, MOM or CPF cares which digits you hold, and no bank will open an account faster because your number ends in a run of 8s.

The cases where it does earn its money are narrower and more specific:

• Businesses whose UEN is genuinely customer-facing and quoted often, such as those tendering frequently or issuing high volumes of invoices to small buyers.
• Businesses where the digits carry commercial weight with the customer base, which in parts of the Singapore market is a real and measurable effect rather than a superstition.
• Founders who intend to hold the entity for decades and who treat the number as part of the brand, in the same way a memorable phone number or vehicle plate is treated.

If none of those describe you, put the $1,000 into your first year of corporate secretarial compliance instead. You will get more out of it.

Frequently asked questions

Can I buy a Special UEN for my existing company?
No. A SUN can only be selected while you are registering a new entity, at the payment stage of that transaction. Once the entity is registered and a UEN has been allocated, there is no application, fee or filing that will change the number. This is the single most common disappointment with SUNs.

How much does a Special UEN cost in Singapore?
ACRA prices SUNs in two tiers. Tier one covers consecutive identical digits and any pattern containing the digit 8. Tier two covers repetitive patterns without an 8, and blocks ending in three identical digits. Tier one is the more expensive of the two. Verify the current amounts on ACRA’s SUN page before you budget.

Is the SUN fee refundable if I change my mind?
No. SUNs are stated by ACRA to be non-refundable and non-exchangeable. You cannot swap the block you bought for a different one, and you cannot get the fee back. Check the digits carefully at the confirmation screen, because that is your only opportunity.

Does a SUN cost anything to keep each year?
No. The fee is paid once, as part of the registration transaction. There is no annual renewal, no maintenance charge and nothing to re-file. Your ordinary annual obligations, such as the annual return, are unaffected by whether you hold a SUN.

Will my SUN change if I change my company name?
No. A UEN, special or otherwise, attaches to the entity rather than to the name. You can change your registered name without affecting the number. The reverse is also true: nothing about holding a SUN restricts your ability to rename the company later.

Can I keep my UEN if I convert my business to a company?
No. Converting a sole proprietorship or partnership into a private limited company creates a new entity, which receives its own new UEN. The old number does not carry over. Certain LLP conversion routes do reopen the SUN selection window, because those also create a new registration.

Getting the registration right the first time

A SUN is a small decision inside a much larger one. The registration transaction you buy it in also fixes your financial year end, your share capital structure, your registered office and your first officers, and every one of those is harder to change afterwards than the number is.

Raffles Corporate Services incorporates Singapore companies and registers businesses, LLPs and LPs every week, and we walk clients through the decisions that stick before they reach the payment screen. If you want a SUN, we will tell you honestly whether it is worth the fee for your business. If it is not, we will say so.

You can confirm the current tiers and the available number list directly on ACRA’s Special UEN guide and on Bizfile’s SUN pages, or read more on Singapore corporate secretarial practice at Singapore Secretary Services.

— The Editorial Team, Raffles Corporate Services