Year-end tax checklist 2025 for private investors in Germany

For private investors in Germany the tax year 2025 has one hard deadline left: a loss certificate (Verlustbescheinigung) must be requested from the bank by 15 December 2025. Everything else on a year-end list can be done until 31 December or later, but it should be checked now: which loss pot your losses sit in, how the exemption orders are spread across your banks, and which papers for fund interests and company stakes the tax adviser will ask for in spring. For anyone who owns more than one securities account, the paperwork saves more tax than any year-end trade.

This article describes the rules and is not tax advice. Your adviser decides the individual case.

The one deadline: loss certificate by 15 December

A German bank offsets gains and losses within its own walls. If your losses at the end of the year exceed your gains there, the bank carries the remainder into the next year and waits for future gains at that same bank.

That is fine with one bank. With two it is a problem. Say you realised a loss of EUR 12,000 on shares at bank A and gains of EUR 15,000 on shares at bank B. Bank B withheld 25 per cent tax plus the solidarity surcharge, together 26.375 per cent, on the full EUR 15,000: EUR 3,956. Bank A knows nothing of this and simply carries your loss forward.

The two can only be netted in the tax return, and only if bank A certifies the loss. Section 43a(3) of the Income Tax Act (EStG) lets you demand that certificate; the request must reach the bank by 15 December of the current year and is irrevocable. Bank A then sets its loss pot to zero, and you declare the EUR 12,000 in Anlage KAP. The tax office offsets it against the gains at bank B and refunds 26.375 per cent of EUR 12,000, which is EUR 3,165, church tax left aside.

Request it only where it helps. If you have no matching gains elsewhere this year, the certificate just moves the carry-forward from the bank to the tax office, where it then has to be declared every year. And miss the date, and the loss stays at bank A for another year.

Two loss pots, and a restriction that is gone

Banks keep two pots. Losses from selling shares may only be offset against gains from selling shares (section 20(6) sentence 4 EStG). All other losses, from funds and ETFs, bonds or certificates, go into the general pot and can be offset against any capital income, including dividends and interest. A share loss therefore does nothing against the dividend of the same company. The Federal Fiscal Court considers the share restriction unconstitutional and referred it to the Federal Constitutional Court on 17 November 2020 (VIII R 11/18); the case is still pending there, and the rule applies.

A third restriction no longer exists. From 2021, losses from forward transactions (Termingeschäfte, such as options and futures) could only be offset against gains from such transactions and only up to EUR 20,000 a year; a similar cap applied to total losses from worthless or defaulted capital claims. The Annual Tax Act 2024, published on 5 December 2024, repealed both without replacement, for all cases still open. Banks are only obliged to apply the change in their withholding from 1 January 2026. So for 2025, look at how your bank has treated such losses. If it still kept them apart, the offset happens in the tax return, and existing carry-forwards from earlier years can be used there without the cap.

This is relevant beyond traders. A private loan that defaults fell under the second of those caps. Whoever lent money to a start-up as a convertible loan and lost it had, until last December, a loss that was usable only in slices of EUR 20,000. We described what a lender owns before conversion in convertible loans: what you own before conversion. How a specific default is treated depends on your stake and the terms, which is a question for the adviser.

Exemption orders: check the split, then set next year's

The saver's allowance (Sparer-Pauschbetrag, section 20(9) EStG) is EUR 1,000 per person and EUR 2,000 for spouses assessed jointly. It only works at source where an exemption order (Freistellungsauftrag) is lodged, and the orders at all banks together may not exceed the allowance.

The usual mistake is an order sitting at a bank where little income arrives while another bank withholds tax from the first euro. Nothing is lost, since the tax office credits the unused allowance in the return, but that is money lent to the state for a year. Look at each bank's year-to-date figures now and shift the amounts. Then set the split for 2026 before January, when banks charge the advance lump sum on accumulating funds.

Foreign withholding tax: credited here, reclaimed there

Dividends from abroad usually arrive after the source state has withheld tax. The bank credits that tax against German tax automatically, but only up to the rate the double taxation treaty allows. The Federal Central Tax Office (BZSt) publishes the creditable rates per country every year.

The part above the treaty rate is not lost and not credited. It has to be reclaimed from the foreign tax authority. Switzerland is the standard example: 35 per cent is withheld, 15 per cent is creditable in Germany, and the remaining 20 per cent can be reclaimed from the Swiss authorities.

Fund interests and GmbH stakes: what to collect

None of the above touches the illiquid part of a portfolio, where banks withhold nothing and report nothing.

For an interest in a closed fund structured as a partnership, the taxable result is determined at fund level and allocated to each investor. You do not calculate it yourself, and the fund's tax statement often arrives long after the year has ended. What the adviser needs from you is proof of what happened in the calendar year: every capital call and distribution notice with its value date, the capital account statement as at 31 December when it comes, and the tax statements for earlier years that arrived during 2025.

For a stake in a GmbH or other corporation, the dividing line is 1 per cent. If you held at least 1 per cent at any time in the last five years, a gain or loss on sale falls under section 17 EStG and is treated as business income; liquidation of the company counts as a sale. Loans you gave or left in place during the company's crisis for reasons of the shareholder relationship can count as additional acquisition cost. Below 1 per cent, a sale is capital income.

The year a loss counts in is often disputed when a company slides into insolvency. You cannot settle that in December, but you can document: the purchase agreement and proof of payment for each round, loan agreements, any waiver or subordination you signed, and the court notices. If a sale of a stake is being negotiated, whether the transfer takes effect in December or in January decides the tax year. Raise it with the adviser before the notary appointment, not after.

The checklist

By 15 December 2025:

• Compare realised gains and losses per bank and per pot. Request a loss certificate where another bank holds matching gains.

By 31 December 2025:

• Adjust exemption orders to where the income actually arrives; set the split for 2026.
• Check how your bank treated losses from forward transactions and defaulted claims in 2025.
• List foreign dividends and note where a reclaim abroad is open.
• If a stake is being sold or a company is being wound up, clarify the tax year with the adviser.

For the tax return in 2026:

• Capital call and distribution notices for 2025, per fund, with value dates.
• Tax statements from funds that arrived in 2025, for whichever year they concern.
• For each company stake: purchase documents, payments, loans, and anything that changed in 2025.

The last block is the one that takes longest in spring, when the documents sit in three mailboxes and a download folder. We keep ours in Valued, where each notice is filed with the fund it belongs to and the year's cash flows can be exported for the adviser. Any orderly folder does the same. What matters is that the collecting happens in December, while you still remember what each letter was about.