Taxes
German portfolio transfer: the 30% fallback trap
The transfer itself costs no tax. The data file that fails to travel with it does.
Last updated: 22 September 2026 · By The Acutic Research Team
Moving a German securities account to another bank costs nothing and, for tax purposes, is a non-event — as long as one unremarkable data file travels with it. When it does not, the non-event turns into a tax bill years later that bears no relation to the actual gain. What gets transferred, when it fails, and how to claw it back.
Two cases worth keeping apart
Every transfer falls into one of two categories, and everything downstream depends on which.
Without a change of creditor — your own account moves to a different bank — there is no disposal. Nothing is realised and nothing is taxed. § 43a (2) sentence 3 EStG expressly obliges the transferring domestic paying agent to pass the acquisition data to the receiving one: purchase price, purchase date, quantity. Between two German banks this happens automatically.
With a change of creditor — the account passes to another person — the transfer is treated as a disposal and unrealised gains are taxed as if everything had been closed out. That can be avoided, but only actively: tell the bank the transfer is gratuitous, and taxation does not occur while the acquisition data passes to the recipient.
When the data does not arrive
The interesting case is the first one — tax-neutral, but with no data. The statute holds a flat rate ready for it:
“Sind die Anschaffungsdaten nicht nachgewiesen, bemisst sich der Steuerabzug nach 30 Prozent der Einnahmen aus der Veräußerung oder Einlösung der Wirtschaftsgüter.” — § 43a (2) sentence 7 EStG
Two words carry the weight. Einnahmen — proceeds, not gain. The base is 30% of what comes in on the sale, wholly independent of what the security once cost. And nicht nachgewiesen — it is enough that the bank does not have the data; whether anyone was at fault is irrelevant.
What that costs
Three accounts, the same securities, the same €50,000 of proceeds — only the cost base differs. Without acquisition data the bank withholds the identical amount in all three.
| Cost base | Actual gain | Correct tax | Under the 30% rule | Overpaid |
|---|---|---|---|---|
| 45,000 € | 5,000 € | 1,318.75 € | 3,956.25 € | 2,637.50 € |
| 50,000 € | 0 € | 0.00 € | 3,956.25 € | 3,956.25 € |
| 52,000 € | −2,000 € | 0.00 € | 3,956.25 € | 3,956.25 € |
All three rows: 50,000 of proceeds at 26.375% (25% withholding plus the 5.5% solidarity surcharge), no church tax and no saver’s allowance. The substitute base is identical in all three — the cost base plays no part in it.
The last row is the uncomfortable one. At a cost base of €52,000 a loss of €2,000 was realised — and the bank still withholds €3,956.25. The substitute base does not recognise losses.
When it happens in practice
Between two German institutions the data transfer is the norm and usually silent. It tends to fail in these situations:
- Transfers from abroad. § 43a (2) sentence 5 EStG admits evidence only from the states it lists; “in allen anderen Fällen ist ein Nachweis der Anschaffungsdaten nicht zulässig” (sentence 6). The correction then has to run through the annual assessment.
- Old or much-moved positions. Securities that have already been transferred several times sometimes shed their history along the way.
- Accounts received from someone else — inherited or gifted, where the notification to the bank was never made.
The condition usually surfaces only at the sale. To find out sooner: in the new bank’s portfolio view, affected positions typically show no cost base at all, or a note that the acquisition information is missing.
It can be recovered
The deduction is a prepayment, not a final figure. The annual tax return — Anlage KAP — corrects it to the actual gain where that can be evidenced: the original contract note, statements showing the cost base, annual tax certificates from the previous bank.
Which leaves one genuinely preventive step, and it is free: export and keep the statements before the transfer. Access to the old online banking tends to disappear faster than expected. Our broker guides cover how, for comdirect, DKB and ING.
A second point easily missed at a switch: loss pots and the Freistellungsauftrag do not move with the account. That is covered in the piece on the two loss pots.
For keeping sight of positions spread across institutions after a switch, the Acutic workspace brings them together without connecting to a bank, with the approach set out on the methodology page. It is not a substitute for a tax computation.
Frequently asked questions
Does transferring a Depot trigger tax?
Not without a change of creditor: moving securities to your own account at another bank is not a disposal. It becomes relevant only if the acquisition data fails to travel with it — the substitute base then applies at the eventual sale.
What is the Ersatzbemessungsgrundlage?
Under § 43a (2) sentence 7 EStG, where acquisition data is not evidenced, withholding is computed on 30 percent of the proceeds of the disposal. Note what that says: 30 percent of the proceeds, not of the gain — and it applies even where there was no gain at all.
Is that money gone?
No. The deduction is a prepayment. The annual tax return, with evidence of the real acquisition cost — old contract notes, statements, annual tax certificates — corrects it to the right figure. Without documents there is nothing to correct with, which is why the old paperwork should outlive the transfer.
What about a transfer from abroad?
For transfers from the states listed in § 43a (2) sentence 5 EStG, evidence of the acquisition data is admissible. In every other case sentence 6 expressly disallows it, so the correction can only run through the annual assessment.
What if the account goes to another person?
A transfer involving a change of creditor is treated as a disposal, so unrealised gains are taxed. If the bank is notified that the transfer is gratuitous — a gift — that taxation does not occur and the acquisition data passes to the recipient. The notification has to be made actively.
This article is general information, not tax advice within the meaning of German law. For your own situation, consult a Steuerberater:in. Legal position: September 2026.
Further reading: The Sparer-Pauschbetrag explained, The Vorabpauschale explained and Trade Republic CSV export. Create free account.
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