§ 20 EStG · IBKR · Anlage KAP

IBKR: Capital Gains Tax & Anlage KAP

From your IBKR Flex-Query export to a complete Anlage KAP. FIFO under § 20 Abs. 4 Satz 7 EStG, ECB daily rates, German loss-offsetting categories, every trade auditable.

The Tax Problem

Sound Familiar?

You trade with Interactive Brokers – low fees, global market access. But when it’s time for your German tax return, the real problem begins: no tax certificate, no capital gains tax withholding, and reports that don’t match German tax law.

  1. No Capital Gains Tax Withholding

    Unlike German brokers, IBKR does not withhold flat-rate tax (Kapitalertragsteuer) and does not issue a tax certificate. You must report all gains and losses yourself in your tax return.

  2. Broker Reports Don't Fit

    IBKR's Activity Statement follows US tax rules – FIFO calculation, currency conversion, and loss offset categories are different under German law. Using those numbers directly can be costly.

  3. FIFO Method Is Required

    German tax law requires the FIFO method (First In, First Out) per § 20 Abs. 4 Satz 7 EStG. IBKR uses different methods by default.

  4. Foreign Currency Gains

    Every transaction in USD must be converted to EUR using the ECB reference rate. This creates additional foreign currency gains or losses.

  5. Time-Consuming Even for Tax Advisors

    Even experienced tax advisors often aren't familiar with the specifics of international brokers. Manually processing IBKR data takes them a lot of time – and costs you a lot of money.

  6. Loss Offset Categories

    Germany has complex loss offset rules: stock losses can only be offset against stock gains, not against options gains.

  7. No Evidence for the Tax Office

    Filling in the numbers on your tax form is the easy part. It gets difficult when the tax office asks: How were these calculated? Where do the values come from? Without complete documentation, you have no proof.

That's What BubbleTax Is For

A tax report that matches German law

BubbleTax handles the entire tax calculation for your Interactive Brokers German tax return. Upload your IBKR data and receive a finished report including Vorabpauschale, partial exemption, and loss offsetting.

What IBKR delivers, what BubbleTax makes of it
AspectIBKR Activity StatementBubbleTax report
FIFO methodUS methods, not accepted in GermanyChronological per § 20 Abs. 4 Satz 7 EStG
Currency conversionUSD-based, no EUR referenceECB daily rate per booking, FX gains separate
Loss offsettingNot reportedGerman offsetting categories (stocks, other, derivatives)
Evidence for the tax officeActivity log, no calculationDetail PDF with every trade traceable
Output formatXML / generic activity PDFAnlage KAP values plus detail report, print-ready

The detail report documents every single calculation step by step. When the tax office requests evidence, you have it in black and white.

Coverage

What BubbleTax Calculates

A complete calculation of your IBKR capital income under German tax law. Each item links to its own deep-dive page.

CRS / DAC

Does IBKR Report to the German Tax Office?

Yes – but not the way you might think. Under the automatic exchange of information (CRS/DAC), IBKR Ireland reports certain data to the German tax authorities. However, this is only account-level metadata:

  • That a brokerage account exists and which asset classes it holds
  • The cash balance and total sum of capital income
  • No tax-prepared data: no FIFO calculation, no ECB conversion, no loss offsetting

So the tax office knows you have an IBKR account – but the actual tax calculation under German law is still your responsibility. That's exactly what BubbleTax is for.

FAQ

What traders ask us before uploading

Why can't I just use the IBKR report?

The IBKR Activity Statement is based on US tax law. The FIFO calculation, currency conversion, and loss offsetting are different under German law. Direct adoption leads to incorrect tax returns.

Do I still need a tax advisor?

BubbleTax creates the tax report. For filing your tax return and individual tax questions, we recommend consulting a tax advisor.

What IBKR data does BubbleTax need?

You need the Flex Query export (Activity Statement) as an XML file. BubbleTax processes all included trades, dividends, interest, and corporate actions.

Does BubbleTax also work for CapTrader and Lynx?

Yes! CapTrader, Lynx, and other IBKR resellers use the same platform. BubbleTax supports all brokers that can export IBKR Flex Queries.

What if the tax office has questions?

The BubbleTax detail report documents every single calculation transparently – which buy was matched with which sell, at which ECB rate it was converted, and how the gain or loss arose. You can trace every number on your tax form back to the original transaction.

Why is there no IBKR tax certificate?

Interactive Brokers is headquartered in Ireland and is not a German credit institution. Therefore, IBKR does not issue an annual tax certificate per § 45a EStG and does not withhold flat-rate tax. You are required to declare your capital income yourself in Anlage KAP. This also applies to introducing brokers such as LYNX, CapTrader, or BANX.

Does IBKR report my account to the tax office?

Yes, under the automatic exchange of information (CRS), IBKR Ireland reports certain account data to the German tax authorities. This includes the existence of the account, the cash balance, and total capital income – but no tax-prepared data. The FIFO calculation, ECB conversion, and loss offsetting under German law are still your responsibility.

How much does an IBKR tax calculation cost at a tax advisor?

Manual processing of IBKR data by a tax advisor can easily cost several hundred euros – and significantly more depending on transaction volume. Many tax advisors aren't familiar with the specifics of international brokers. BubbleTax handles the entire calculation automatically, and you can pass the finished report directly to your tax advisor.

Free Preview

Try it. It's free.

Upload your IBKR data and check the preview. You only pay when you're convinced by the report.