What a Y-tunnus is

A Y-tunnus is the identity number the Finnish state gives your company, and in practice it is the only number that matters. It has seven digits, a dash and one check mark, so it looks like 1234567-8. The Business Information System issues it as soon as the start-up notification goes through, which for an online notification happens straight after you sign, pay and send.

The number belongs to the legal person, not to the brand or the owner. A company keeps the same business ID for as long as it exists, through a change of name, a change of address, a change of industry and a change of owners. That is exactly why a Finnish buyer trusts it more than anything you write about yourself.

A private trader gets one too. There is no lightweight version for small companies, and no separate number for the web shop.

Where the business ID goes on a Finland website

Two places cover almost everything: the footer of every page, and the contact page next to the company name. Both cost nothing to maintain, because the number never changes once you have it.

The written duty is narrower than that habit. Companies entered in the Trade Register, the VAT Register, the Prepayment Register or the Employer Register have to state the business ID on their invoices, business letters and forms, which is how ytj.fi puts it. A website is not named in that list. But the pages where you ask a stranger to send money or personal data behave exactly like a business letter, and a missing number there reads as something being hidden.

The cheapest fix in the whole of this article is a footer line you write once.

What the law wants visible on the site

For a site that sells to consumers, the hard list comes from consumer law. The Finnish Competition and Consumer Authority sets out what has to be given before a distance contract is made: the company name, the geographical address of the head office, an email address for consumer contact, a phone number with the cost of the call made clear, the business ID and the register entry, the complaint procedure if it is anything unusual, and the competent dispute resolution body.

For a site that only presents the company and collects enquiries there is no equivalent list. What there is instead: a legal name that matches the register, an address that exists, and a way to reach a human being. Three things, and most small business sites in Finland get at least one of them wrong.

The worst version is a site trading under a marketing name with the registered name nowhere on it. A cautious buyer will look, and finding nothing is a reason to stop looking.

Foreign companies selling to Finland

A foreign company needs no Finnish business ID to run a website in Finnish or in English. It needs one once it registers here for VAT, opens a branch, or becomes an employer in Finland, and from that point the number appears in the YTJ search like any domestic company.

What a foreign seller does owe a Finnish consumer is the same pre-contract information, in a language the buyer can actually read, with the trader identified by its real registered name and the register it sits in at home. A Swedish organisationsnummer or a German Handelsregister entry fills that slot perfectly well. An empty slot does not.

The real obstacle here is credibility rather than law. A site with a .fi address, prices in euros and no identifiable company behind it looks like the kind of shop the consumer press warns about every November. If the .fi address matters to you, the rules on who can register a .fi domain are worth reading before you plan a launch date.

Where customers check you

The first stop is the company and organisation search at ytj.fi, which is free and open to anyone. It returns the business ID, the registered name and any auxiliary names, the domicile, the line of business, and the registers the company has been entered in, including the Trade Register, the Prepayment Register, the Employer Register and the VAT Register.

Purchasing departments go further, into the Trade Register at prh.fi for the officially registered details. Credit information companies sell what is left. None of this is something you can influence on the day somebody looks, which is the whole point of it.

So the number on your website works as a pointer into a public record. Put the wrong one there and you do not look careless. You look like a different company.

The registers behind the number

One number, several registers, and the registers are what a professional buyer actually reads. The Trade Register at PRH holds the company itself. The Tax Administration holds three more: the VAT Register, the Prepayment Register and the Employer Register.

The Prepayment Register is the one that changes commercial conversations. A Finnish business buying services from a supplier who is missing from it has to withhold tax from the payment, so most buyers avoid the situation altogether. Subcontractors in construction, cleaning and consulting know this and expect to be checked before anything is signed.

None of it needs explaining on your website. It only needs the number to be easy to find, so the check takes ten seconds instead of an email and two days.

The registered name, the auxiliary name and the brand

Use the registered name at least once on the site, even when you trade under something shorter. A company registered as Pohjolan Rakennuspalvelut Oy that markets itself as Pohjola Build has to make the first name findable, because that is the name on the contract, on the invoice and in the register.

An auxiliary trade name registered at PRH is a clean way to run a second brand inside the same company. It shows up in the YTJ search under the same business ID, so a buyer who looks it up lands exactly where you want them to land.

The footer pattern that works needs no explanation around it: brand name, registered company name, business ID, address.

Four items and the footer is finished: registered company name, business ID, street address with postcode and town, and one contact route that a human answers. Repeat it on every page, because visitors arrive from Google on a service page rather than on your front page.

Add the VAT number when you sell across borders. In Finland it is the business ID with the dash removed and FI in front, so 1234567-8 becomes FI12345678. Buyers elsewhere in the EU ask for it and check it, so having it there saves an email in both directions.

Keep all of it as real text rather than as part of an image. Text can be copied, read aloud by a screen reader and found by a search engine. An address baked into a picture fails all three at once.

The contact page a Finnish buyer expects

A street address, not a post box, and a named person or at least a named team. The address matters even for a company that never receives visitors, because it tells the reader which country and which courts are in play if something goes wrong.

Opening hours belong on this page when you answer the phone at set times. A number that rings out at a quarter past four on a Friday does more damage than no number at all.

Put the business ID here as well as in the footer. This is the page people screenshot and forward to their accounting department, and it should carry everything that department needs.

What an online store has to add

An online store adds the full pre-contract list, readable before the customer pays rather than buried in the terms. Prices with VAT included, delivery costs, delivery time, payment methods, the right of withdrawal and how to use it, the address a return goes to, and an order button worded so it makes clear that the order creates an obligation to pay.

That last point is specific and frequently wrong. A button that says Continue, or Send, at the step where the customer commits does not do what the rule asks of it.

If the shop is still being planned, our note on what starting an online store in Finland takes goes through the rest of that list in order.

The same details in every language

Keep the company details identical in each language version, letter for letter. A registered name is not translated, an address is not translated, and the business ID has no local variant. Translate the labels around them and leave the values alone.

The usual bug is a Finnish footer carrying the full details and an English footer carrying a friendly sentence and an email address. The English page is often the first thing a foreign buyer reads before a first order, which makes it the worst page to thin out.

Where the site runs on a content management system, check that the footer is one shared block rather than a copy per language. Copies drift apart within a year.

Keeping it right when things change

Change the address on the site in the same week you notify PRH, not in the same quarter. An address that no longer matches the register is the most common mismatch we find on small business sites, and it usually dates back to a move two years earlier that nobody thought to mention to the web person.

Name changes, new auxiliary names and a change of domicile all follow the same order: register first, website second, invoice templates third. The business ID itself survives all of it untouched.

When nobody on your side owns this job, a light content management system that lets you edit the footer in a minute is worth more than a yearly support ticket to an agency.

Common mistakes we see

Five turn up again and again, roughly in this order of frequency: no business ID anywhere on the site, the marketing name with no registered name, an old address, a VAT number still written with the dash in it, and company details that exist in Finnish but never made it into the English version.

A sixth deserves its own line. Details that live only inside an image or a downloadable PDF. They pass a human glance and fail a screen reader, a copy and paste, and a search engine.

None of these cost money to fix. They cost orders for every month they stay there.

A short checklist before you publish

Work down this list and the identification side of the site is done.

  • Registered company name and business ID in the footer of every page, as text.
  • Street address with postcode and town, matching what the Trade Register holds.
  • One contact route a human answers, with the hours when they are limited.
  • VAT number in FI format when you sell outside Finland.
  • The same details on every language version, from one shared block.
  • For a shop, the full pre-contract list and a pay button that says what it does.

If you want a second pair of eyes on an existing site, we run a free review and this is one of the things it looks at.