Q2 VAT return: deadline end of August – how to avoid late-payment interest

Which deadlines now apply

Businesses filing quarterly must submit the return for the second quarter (April to June) within 60 days of the quarter’s end and pay the tax due within the same period – in concrete terms, by 31 August 2026. The same deadline applies to companies using net tax rates with semi-annual filing: their return for the first half of 2026 is also due at the end of August. Businesses that have switched to annual VAT filing do not need to file a quarterly return, but should transfer the instalments set by the FTA on time – otherwise interest accrues here too.

Companies that outsource their VAT return need to be particularly careful: even the best fiduciary can only account for what is on the table. If the second quarter’s documents only arrive in mid-August, a clean reconciliation becomes a race against time. Our recommendation: hand over your records before the company holidays, not after. That leaves enough time for queries – about missing supplier invoices or unclear bookings, for example – and the return goes out without haste and without any risk of late-payment interest.

Late-payment interest now at 4.0 percent

Since 1 January 2026, late-payment interest on federal taxes and levies has been a uniform 4.0 percent, down from 4.5 percent the previous year. The reduction stems from the annual review of interest rates by the Federal Department of Finance. Important to know: for VAT, late-payment interest is owed without any reminder – it starts to run automatically once the payment deadline expires. Four percent may not sound like much, but it adds up quickly on larger tax amounts: on a VAT liability of CHF 50,000, a quarter-year’s delay already costs around CHF 500 – money that is easily saved with a little planning.

Deadline extension: possible, but no free pass

If you cannot complete the return in time, you can request a filing extension in the FTA’s ePortal with a few clicks – usually for up to three months. But beware: the extension only covers the filing of the return, not the payment deadline. Late-payment interest still starts running in September. The proven solution: transfer a provisional payment in the amount of the tax you expect to owe, on time. If the final return comes in lower, you get the difference back; if it is higher, interest accrues only on the remaining balance.

Typical errors in the quarterly return

In our advisory practice we see the same pitfalls again and again: input tax deductions without proper receipts, forgotten private shares – for the company car, for instance – incorrectly allocated supply dates on invoices around the quarter change, or missing corrections for bad debts. The platform taxation rules in force since 2025 also continue to cause uncertainty: anyone selling via online marketplaces must check whether the platform assumes the VAT liability for those sales. A clean turnover reconciliation between the accounts and the return uncovers most errors before the FTA finds them – and spares you unpleasant surprises in a later audit.

How to reduce the burden for good

Recurring quarterly stress is usually a symptom, not a law of nature. If you capture receipts digitally as you go instead of ploughing through folders every quarter, the return is done in a fraction of the time. Companies with taxable annual turnover of up to CHF 5,005,000 can also examine whether annual VAT filing would ease their workload – provided the tax is set aside in a disciplined way. And if you would rather hand the return over entirely, delegate it to a fiduciary partner who keeps track of deadlines, instalments and special cases.