OSS VAT Returns in Tulos.ai: Selling to EU Consumers Without the Paperwork

When your sales to EU consumers are taxable in another EU country, the One Stop Shop (OSS) lets you report that VAT through Finland instead of registering separately in each country for those sales. You file one quarterly return to the Finnish Tax Administration (Vero), and Tulos.ai prepares the data for you.

In Tulos.ai, OSS returns are filed through a CSV upload rather than a direct submission to Vero: you download the file and upload it to the return in MyTax (OmaVero). Tulos.ai brings the VAT codes, invoices and bookkeeping entries into the same workflow; you review the data before submitting.

Tulos.ai’s menus are in Finnish, so this guide gives the Finnish label first, with a translation where it helps.

Also available in Finnish and Russian.

Table of Contents

1. When OSS applies
2. Step 1: switch OSS on
3. Step 2: create the VAT codes you need
4. Step 3: invoice your EU consumers
5. Step 4: file the quarterly return
6. What stays on the Finnish VAT return
7. Good to know
8. Official guidance
9. Summary

When OSS applies

This guide covers a Finnish VAT-registered business dispatching goods from Finland and selling eligible services to consumers in other EU countries. The Union scheme covers EU distance sales of goods and consumer services taxable in an EU country where the seller has no establishment.

The €10,000 annual threshold, excluding VAT, applies to the combined total of cross-border EU distance sales of goods and telecommunications, broadcasting and electronic services. For a business established only in Finland, with goods dispatched from Finland, these sales can remain subject to Finnish VAT if the total does not exceed the threshold in either the current or the previous calendar year. Finnish domestic sales do not count towards it.

If the threshold is exceeded, those sales become subject to destination-country VAT. Register for the Union scheme in MyTax to report them through Finland, or register locally where required. You can also opt for destination-country taxation and OSS below the threshold. Other consumer services follow their own place-of-supply rules; the €10,000 threshold does not apply to them. Vero explains the scope and threshold here.

Finnish domestic sales and sales to businesses stay outside this OSS workflow and follow the normal VAT reporting rules. For business-to-business EU sales, see our guide to EU sales and reverse-charge VAT.

Step 1: switch OSS on

Asetukset → Veroasetukset → OSS (One Stop Shop) (Settings → Tax settings)

1. Register for the Union scheme in MyTax first, under EU:n alv-järjestelmät → Rekisteröityminen arvonlisäveron erityisjärjestelmään (EU VAT schemes → registration for a VAT special scheme).
2. In Tulos.ai, turn on OSS-rekisteröity (OSS registered) and set Rekisteröity alkaen (registered from) to the start date of your registration.
3. Check OSS-maksuviite (OSS payment reference), which Tulos.ai uses for the tax invoice. MyTax provides a return-specific payment reference after submission. Confirm the correct reference each quarter before paying; do not reuse your ordinary VAT reference.
4. Save.

After you save, Kirjanpito → Veroilmoitukset → OSS-ilmoitus (Bookkeeping → Tax returns → OSS return) appears in the menu, and OSS VAT codes become available on sales invoices. Companies that are not registered see nothing OSS-related.

Step 2: create the VAT codes you need

Kirjanpito → Veroilmoitukset → OSS-ilmoitus → OSS-verokoodit (Bookkeeping → Tax returns → OSS return → OSS VAT codes)

Add one code for each country and VAT rate you sell at, for example Germany 19 % goods, Germany 7 % goods or France 20 % services.

• Pick the Kulutusjäsenvaltio (country of consumption). Tulos.ai fills in that country’s standard rate. The hint under the rate field shows the rate and links to the EU’s VAT rate database (TEDB), where you can check reduced rates.
• Change the rate if the code is for a product category with a reduced rate.
• Pick Myynnin laji (type of sale): goods or services.
• Press Lisää koodi (add code).

The new codes post VAT to account 29394 OSS-arvonlisäverovelka (OSS VAT liability), which keeps OSS VAT apart from Finnish VAT. A code that has already been used on invoices cannot be deleted. If a country changes its rate, add the new rate as a new code.

On the invoice lines, use the revenue accounts 3365 Tavaramyynti EU-kuluttajille (OSS) for goods and 3345 Palvelumyynti EU-kuluttajille (OSS) for services. OSS sales then show up on their own lines in the income statement.

Step 3: invoice your EU consumers

Create the customer as a private person, with the Yritys (company) switch off, and set the correct country.

On a sales invoice to that customer, each line’s VAT selector offers that country’s OSS codes. New lines get the highest-rate goods code by default. If you’re selling services or reduced-rate goods, pick the appropriate code. For services, confirm the place of taxation before choosing an OSS code; the customer’s address alone does not determine it.

To credit an invoice, use Hyvitä (credit) on the original invoice. The credit note stays linked to the original, and Tulos.ai uses that link to report corrections for earlier quarters automatically.

Step 4: file the quarterly return

The OSS return covers a calendar quarter. Both the return and payment must reach Vero by the last day of the following month: Q3 is due on 31 October. Weekends and public holidays do not extend the deadline, so allow time for the bank transfer. File a return for every quarter, including a zero return when there are no sales or corrections. Vero’s filing and payment guidance sets out the deadlines.

Kirjanpito → Veroilmoitukset → OSS-ilmoitus

1. Create the return

Select the quarter and press Luo ilmoitus (create return). Tulos.ai adds up the posted invoices and credit notes that carry OSS codes. It groups them by country, type of sale, standard or reduced rate, and the rate itself.

2. Check the return page

Three sections can need your attention:

• Tarkistettavat rivit (rows to check) lists invoice lines that carry an OSS code even though the customer doesn’t qualify: a company, a Finnish customer, or a customer in a different country than the code’s. Fix those invoices and press Päivitä rivit (refresh rows). You can’t download the CSV until this list is empty.
• Negatiiviset ryhmät (negative groups) appear when credit notes for a country add up to more than that quarter’s sales there. Trace the credits to the original periods and add any necessary earlier-period corrections in MyTax. The current-period sales section cannot be negative; the corrections section can.
• Korjausrivit aiemmille kausille (corrections for earlier periods) are created automatically from credit notes whose original invoice was booked in an earlier quarter.

3. Download the CSV

Press Lataa CSV (download CSV). The file is named after the quarter, for example oss-Q3-2026.csv, and follows Vero’s upload format.

4. Upload it to MyTax

In MyTax, open the OSS return for the quarter and upload the file. Review the rows MyTax shows, then submit. MyTax checks the rows before anything is filed. If it reports an error, fix the invoice in Tulos.ai, refresh the rows and download the file again.

5. Mark the return as filed

Back in Tulos.ai, press Merkitse ilmoitetuksi (mark as filed). This locks the return and posts a bookkeeping entry that moves the declared amount from 29394 to 29481 OSS-arvonlisävero, maksettava (OSS VAT payable). That way, 29394 only ever holds VAT that hasn’t been declared yet. A link in the return header opens the entry.

6. Create the tax invoice and pay it

Press Luo verolasku (create tax invoice). Tulos.ai creates a purchase invoice to Verohallinto with the OSS deadline. Before paying, compare its amount, bank account and payment reference with the payment details for the submitted return in MyTax. Use that return’s reference and pay the amount MyTax shows as payable; correct the invoice if needed. The bank payment is matched to the invoice and clears account 29481.

Each OSS return has its own payment reference, as explained in the European Commission’s OSS payment guidance.

Need to redo a return?

If you need to recompute a return after marking it filed, press Peru ilmoitusmerkintä (cancel filed status). Tulos.ai reverses the bookkeeping entry with a counter-entry instead of deleting it. You can then recompute the return and mark it filed again.

This changes only the status and bookkeeping in Tulos.ai. It does not cancel or amend a return already submitted in MyTax. Correct a submitted OSS return on a later return, usually within three years of the original deadline, following Vero’s correction instructions.

What stays on the Finnish VAT return

Tulos.ai leaves sales booked with OSS codes out of the Finnish VAT return and the EU recapitulative statement. Your domestic sales and other reportable transactions stay on the normal returns. You cannot deduct purchase VAT on an OSS return: claim deductible Finnish purchase VAT on the Finnish VAT return where entitled, and handle foreign purchase VAT through the applicable local return or refund procedure.

Good to know

• Corrections are automatic only for Hyvitä credit notes. A credit note written from scratch isn’t linked to an original invoice, so Tulos.ai counts it in the quarter it’s booked. If it relates to an earlier declared quarter, allocate the correction to that period in MyTax.
• Foreign currencies: the OSS return uses the ECB exchange rate for the last day of the quarter, or the next publication day if no rate was published then. Check the exported euro amounts against this rule, especially if the bookkeeping used invoice-date rates. See Vero’s detailed guidance, section 5.1 (in Finnish).
• Greece is EL in the file, as Vero requires. Everywhere else in Tulos.ai it’s GR.
• Rates: Tulos.ai keeps the standard rates up to date. Each country sets its own reduced rates and decides which product categories they cover, so check them in the EU’s TEDB database, which is linked from the OSS code card.

Official guidance

• Vero: OSS schemes and eligibility
• Vero: Registration in MyTax (in Finnish)
• Vero: CSV upload format

Summary

1. Register for the Union scheme in MyTax.
2. In Tulos.ai, switch on OSS, set the start date and check the payment-reference setting.
3. Create an OSS VAT code for each country and rate you sell at.
4. Invoice EU consumers as private customers, and use Hyvitä for credit notes.
5. Each quarter, create the return, clear the rows to check, download the CSV and upload it to MyTax.
6. Mark the return as filed, create the tax invoice, verify the return-specific payment details in MyTax and pay early enough to meet the deadline.

Selling to consumers across the EU? Tulos.ai keeps OSS sales, VAT codes and bookkeeping entries in one place, making the quarterly return easier to prepare and check. Try it →