OSS this autumn: the Q3 return, the rates that moved, and what ViDA changes by 2028.
The July–September return is due by 31 October. Four standard rates have changed since 2024, and the EU’s VAT in the Digital Age package reshapes the One-Stop Shop from 2027. A checklist for a Shopify store selling across the EU.
A store that sells to consumers in other EU countries above €10,000 a year charges each customer the VAT of the country the goods arrive in, and declares all of it in one quarterly return through the One-Stop Shop in its home country. The third quarter of 2026 closes on 30 September.
The Q3 return
- The return for July, August and September 2026 is due by 31 October 2026, and so is the payment.
- A store registered for OSS files even in a quarter with no cross-border sales — a nil return.
- The VAT declared is the destination country’s rate, applied to what each order actually charged. It is not your home rate, and it is not an average.
Four rates that moved
The most common error in an OSS return is not a missed sale. It is an out-of-date rate table: a store charging, or a report assuming, a rate the country no longer uses. These four changed recently and are the ones most likely to be wrong in a spreadsheet written before them.
| Country | Before | Now | Since |
|---|---|---|---|
| Estonia | 22% | 24% | July 2025 |
| Romania | 19% | 21% | August 2025 |
| Slovakia | 20% | 23% | January 2025 |
| Finland | 24% | 25.5% | September 2024 |
If a theme, an app or a tax override still prices Estonian orders at 22%, the store collects two points too little on each one and owes the difference from its own margin.
What VAT in the Digital Age changes
The ViDA package was adopted on 11 March 2025 and comes in over a decade. Three dates matter to an online store.
- 1 January 2027 — small changes for OSS and IOSS users, including a new mechanism for correcting earlier returns and monthly IOSS listings per member state.
- 1 July 2028 — the Single VAT Registration measures begin. The One-Stop Shop is extended, transfers of a store’s own goods between EU countries — stock moved to a warehouse abroad — can be reported through it, and the call-off stock simplification ends. A mandatory reverse charge applies to suppliers not identified in a country.
- 1 July 2030 — digital reporting and e-invoicing for cross-border business-to-business supplies.
For a store that keeps stock in more than one EU country, 2028 is the date that may remove the need for a separate VAT registration in each. For a store that ships from one warehouse, the practical change is smaller: the return it already files gets a proper way to correct itself.
What Profflow does with it
Profflow takes VAT out of revenue before calling anything profit, order by order from the tax each order recorded, and splits it by destination — the figure an OSS return asks for, per country, for any quarter. Because each order carries the tax it was actually charged, a rate change shows up on the orders after it and leaves the ones before it alone.
