Interactive Brokers (IBKR) and German Taxes — 2025 Filing Guide

1. The IBKR tax situation in Germany

Interactive Brokers is not a German inländische auszahlende Stelle. For a German tax-resident private investor using a non-German IBKR entity, IBKR does not run the German Abgeltungsteuer workflow that a German broker (Trade Republic, Scalable, Comdirect, ING) does. IBKR's own tax pages frame their reporting as dependent on the user's tax residency and applicable laws, and tell non-U.S. / non-Canadian customers that they generally receive information statements rather than country-specific tax declarations (IBKR — Tax Residency).

The practical consequence is that you self-declare IBKR income on Anlage KAP for non-fund capital income (foreign dividends, interest, bond coupons, share-sale gains/losses) and on Anlage KAP-INV for investment-fund income (ETF distributions, Vorabpauschale, fund sales). ELSTER's 2025 help confirms that Anlage KAP-INV is the form for investment income not subject to domestic withholding, including investment fund units held in a foreign custody account (ELSTER — Anlage KAP / KAP-INV 2025 help).

2. What IBKR doesn't withhold for you

For private capital income at a foreign-broker custody account, IBKR generally does not withhold or remit any of the following German taxes:

• 25 % Kapitalertragsteuer under the Abgeltungsteuer regime (§ 32d EStG).
• 5.5 % Solidaritätszuschlag on the assessment base of Kapitalertragsteuer.
• Kirchensteuer, where applicable, via the BZSt's automated retrieval system.
• Vorabpauschale for investment-fund units held abroad — IBKR does not deduct this annual deemed-income figure (§ 18 InvStG).

IBKR may withhold source-country tax — typically U.S. dividend withholding under Form 1042-S (IBKR — Form 1042-S). That is not German withholding. It may be creditable in Germany via Anlage KAP line 41, subject to treaty limits, but it does not replace the German assessment.

You also cannot apply a German Freistellungsauftrag at IBKR. Freistellungsaufträge under § 44a EStG are part of the German domestic-bank withholding process. With IBKR, the Sparer-Pauschbetrag is applied through your tax assessment instead — see Section 8.

3. Reports to download from IBKR

For German filing, treat IBKR reports as source data, not as a German Steuerbescheinigung. IBKR's own tax pages caution that their tools and statements are informational (IBKR — Tax Reporting).

Activity Statement / Annual Statement

The Activity Statement is the master audit trail. In Client Portal, navigate to Performance & Reports → Statements (or Menu → Reporting → Statements), pick an account, choose the statement type and a custom annual period, and export PDF / CSV / HTML (IBKR — Statements). Annual Activity Statements are normally available by 31 January of the following year. Use a 1 January 2025 – 31 December 2025 custom range for the 2025 return.

Custom Activity Statement

Build a German-tax-friendly template that includes Trades, Dividends, Withholding Tax, Cash Report, Broker Interest, Bond Interest, Forex P/L Details, Corporate Actions, Open Positions, Transfers, and Realized P/L (IBKR — Create Custom Statement). CSV is usually the most reconcilable format.

Dividend Report

The Dividend Report breaks out dividends and payments-in-lieu by revenue type, with withholding amounts shown separately, in your account base currency (IBKR — Tax Reporting (non-U.S.)). For Anlage KAP, you usually need the gross dividend and withholding tax per payment date, not net base-currency totals.

Form 1042-S

For non-U.S. clients, IBKR issues Form 1042-S covering U.S.-source income subject to U.S. withholding. IBKR's tax-reporting calendar puts the 2025 Form 1042-S availability at March 16, 2026 (IBKR — non-U.S. Tax Forms). Use it to substantiate U.S. withholding when claiming a credit on Anlage KAP line 41.

Flex Queries

For lot-level, dividend-level and FX-level CSV/XML extracts, run a Flex Query (IBKR — Report Menu). For German filing, Flex Queries are the easiest way to build a spreadsheet-ready export.

Tax Optimizer and Position Transfer Basis

The Tax Optimizer lets you change tax-lot matching methods and view year-to-date P/L (IBKR — Tax Optimizer). Use it to inspect lots; do not let it override the German FIFO requirement (Section 5). The Position Transfer Basis page lets you enter cost basis for transferred positions (IBKR — Position Transfer Basis). If you transferred positions in, fill this in — otherwise IBKR may show zero or wrong cost basis.

Forex P/L Details

The Forex P/L Details report shows currency-trading activity, closed lots, basis, realized P/L and the spot-rate handling per transaction type (IBKR — Forex P/L). See Section 4 for how to handle foreign-currency events on Anlage KAP — do not blindly treat IBKR Forex P/L as taxable § 20 EStG capital income.

4. Currency conversion: from USD to EUR for German filing

Your German return is in euros. The rule is not "use IBKR's base-currency P/L". It is also not "use a single year-end FX rate".

For capital income in foreign currency, the BMF's Abgeltungsteuer guidance points to the Devisenbriefkurs on the date the income flows to the investor. The same applies to foreign withholding tax (BMF — Einzelfragen zur Abgeltungsteuer (14 May 2025)). For sales and redemptions, BMF guidance and § 20(4) EStG point to the date of the underlying transaction: acquisition costs in EUR at the acquisition date, sale proceeds in EUR at the sale date.

Two distinct cautions:

• The BMF Umsatzsteuer-Umrechnungskurse are monthly VAT rates under § 16(6) UStG. They are not the rule for converting Anlage KAP / KAP-INV capital income.
• IBKR's display-currency conversions use spot rates by transaction type, including trade date for spot/securities and transaction day for interest/dividends/deposits. Useful for reconciliation; not a substitute for German-rule EUR conversion.

Practical mapping for IBKR:

• USD dividend → convert gross at credit date; convert U.S. withholding at the same date.
• USD stock sale → acquisition cost at acquisition date; proceeds at sale date.
• USD ETF distribution / Vorabpauschale / sale → same logic, but the result enters Anlage KAP-INV, not Anlage KAP.
• USD margin interest, broker interest, bond interest → at the credit date.

5. ETFs and funds in Anlage KAP-INV

For investment-fund units held at IBKR — UCITS ETFs, U.S. ETFs, mutual funds — German investment-tax law applies. § 16 InvStG defines investment income as distributions, Vorabpauschalen under § 18 InvStG, and gains from sale under § 19 InvStG. Because IBKR is a foreign-broker custody case, this all goes on Anlage KAP-INV.

Distributions — KAP-INV lines 4–8

The 2025 KAP-INV form lists distributions by fund type, all vor Teilfreistellung:

Vorabpauschalen — KAP-INV lines 9–13

Same fund-type breakdown, also vor Teilfreistellung. ELSTER notes the entry can be "Übertrag aus Zeile 45 oder laut Aufstellung des ausländischen Kreditinstituts" — the worksheet calculation if you do it yourself, or the broker's figure if it provides one (ELSTER — Anlage KAP-INV 2025 help). For 2025 you report the 2024 Vorabpauschale deemed received on 2 January 2025 (see Section 7).

Sale gains and losses — KAP-INV lines 14, 17, 20, 23, 26

Adjacent fields (Z15, 16, 18, 19, 21, 22, 24, 25, 27, 28, 29) handle bestandsgeschützte Alt-Anteile and fiktive Veräußerung for fund units acquired before 1 January 2018. If you started investing through IBKR after 2018, those fields are normally empty.

Worksheet sections — calculation pages

The 2025 ELSTER online form shows two worksheet pages without numbered Zeilen:

• Section 4 "Ermittlung der Vorabpauschalen zu den Zeilen 9 bis 13" — used to calculate the Vorabpauschale per fund and per acquisition month.
• Section 5 "Ermittlung der Gewinne und Verluste aus der Veräußerung von Investmentanteilen zu den Zeilen 14 bis 28" — used to calculate the per-fund sale result, including a field for prior Vorabpauschalen during the holding period (avoids double taxation).

Teilfreistellung — applied by the Finanzamt

You enter gross amounts in KAP-INV lines 4–28. The tax office applies the partial exemption per § 20 InvStG:

FIFO is not optional

For securities in collective custody, the BMF's Abgeltungsteuer guidance applies FIFO per individual custody account: the units acquired first are treated as sold first, regardless of any client instruction (BMF — Abgeltungsteuer (14 May 2025)). IBKR's Tax Optimizer can match lots on different methods — for inspection, fine. For German filing, apply FIFO.

6. Stocks and bonds in Anlage KAP

Individual share dividends and bond / cash interest from IBKR are foreign capital income for a German resident. They go on Anlage KAP, not KAP-INV. Verified 2025 ELSTER labels for the foreign-broker section:

ELSTER explicitly says foreign tax connected with KAP-INV income also goes on Anlage KAP line 41, not Anlage AUS (ELSTER — Anlage KAP / KAP-INV 2025 help). Line 17 captures any Sparer-Pauschbetrag already used through Freistellungsaufträge at German banks; if you use IBKR only and have no German Freistellungsauftrag elsewhere, enter 0.

7. Vorabpauschale specifics for 2025

The Vorabpauschale is a minimum-taxation mechanism on investment-fund units. § 18 InvStG deems it received on the first working day of the following calendar year.

Two timing facts that matter for your 2025 return

• The 2024 Vorabpauschale is deemed received on 2 January 2025 and belongs in your 2025 return. ELSTER's 2025 KAP-INV help confirms the 2024 Basiszins of 2.29 % and the resulting calculation rate of 1.603 % (= 70 % × 2.29 %).
• The 2025 Vorabpauschale will be deemed received on 2 January 2026 and belongs in your 2026 return. The BMF letter of 10 January 2025 sets the 2025 Basiszins at 2.53 %, giving a calculation rate of 1.771 % (BMF — Basiszins 2025).

The formula in plain terms

Per fund, per year:

• Basisertrag = January 1 fund value × Basiszins × 70 %.
• Mehrbetrag = (December 31 fund value − January 1 fund value) + distributions.
• Vorabpauschale = min(Basisertrag, Mehrbetrag) − distributions; floor at 0; cap at the Mehrbetrag.

For units acquired during the year, the Vorabpauschale is reduced by 1/12 for every full month before the month of acquisition (§ 18 InvStG). Monthly savings plans therefore need a separate calculation column per acquisition month — ELSTER's Section 4 worksheet supports this.

The line-53 trap on later sales

When you eventually sell a fund, the Section 5 worksheet (≈ line 53 in PDF form) deducts prior Vorabpauschalen during the holding period before partial exemption, to avoid double taxation. For foreign-broker units, that deduction applies only to the extent the prior Vorabpauschalen were actually reported and taxed, or were absorbed by the Sparer-Pauschbetrag — you must be able to document this.

Concretely: if you forgot to report the 2024 Vorabpauschale on your 2025 return, it cannot reduce the gain when you sell the same fund later. The KAP-INV calculator on this site keeps a running record of prior Vorabpauschalen so the eventual sale calculation is correct.

8. The Sparer-Pauschbetrag trap

For 2025, the Sparer-Pauschbetrag is €1,000 single / €2,000 jointly assessed (§ 20 (9) EStG). At a German broker, you can apply this through a Freistellungsauftrag. At IBKR, you cannot — IBKR is not in the German withholding system. The allowance is applied through your assessment.

9. Common mistakes IBKR users make

1. Treating IBKR's withholding as German tax. IBKR may withhold U.S. tax on U.S.-source dividends (typically 30 %, or 15 % under treaty with a valid W-8BEN). That is U.S. source tax, reported on Form 1042-S — not German Kapitalertragsteuer. Claim it as a credit via Anlage KAP line 41 if creditable.
2. Putting ETF distributions in Anlage KAP line 19. Foreign-broker fund distributions belong in Anlage KAP-INV lines 4–8 by fund type, not in the ordinary KAP foreign-income line.
3. Forgetting Vorabpauschale because no cash was paid. Accumulating ETFs typically have no distribution, but the Vorabpauschale still applies whenever the fund's value increase exceeds the Basisertrag.
4. Using a single annual-average FX rate. BMF guidance points to transaction-date conversion — not a yearly average and not the Umsatzsteuer-Umrechnungskurse table.
5. Trusting IBKR realized P/L without checking German FIFO. Tax Optimizer can match lots on multiple methods. Apply FIFO per the Abgeltungsteuer guidance for the German return.
6. Forgetting the Section 5 / "line 53" prior-Vorabpauschalen entry on sale. This is the single most expensive omission on a final fund sale because it can cause double taxation of the same value increase.
7. Transferring positions in without filling Position Transfer Basis. Without that data, IBKR may show zero or wrong cost basis, which feeds straight into a wrong KAP-INV / KAP gain calculation.
8. Treating the IBKR "German Tax Report" as a Steuerbescheinigung. It is informational — see the note in Section 3.
9. Mixing up CRS reporting and your tax return. CRS data exchange is information reporting between tax authorities. It does not file Anlage KAP-INV for you and it does not apply your Sparer-Pauschbetrag.
10. Treating IBKR's Forex P/L as § 20 EStG capital income by default. Private foreign-currency cash gains can fall under § 23 EStG (private disposals) rather than § 20. Inspect each Forex item rather than dumping it into Anlage KAP.

10. Calculate your Vorabpauschale now

Open the calculator, enter your 2024 fund values and any 2024 distributions, and you get the 2025-return Vorabpauschale and the KAP-INV / KAP figures to copy into ELSTER. Free, no signup, data stays in your browser.

Open the Vorabpauschale calculator

11. Disclaimer and sources

Last updated: 2026-04-29.

Sources: BMF (Bundesministerium der Finanzen), ELSTER, Investmentsteuergesetz, Einkommensteuergesetz, IBKR official documentation. We make every effort to be accurate, but tax law and broker reports change and individual circumstances vary.

Disclaimer / Haftungsausschluss: This page is a calculation and filing helper for informational purposes only. It does not constitute tax advisory services (Steuerberatung) within the meaning of the Steuerberatungsgesetz. No advisory or professional relationship is created. The page is not a German Steuerbescheinigung. No guarantee is made regarding the accuracy, completeness, or timeliness of the information. Users are solely responsible for verifying all values before filing their tax return. Always consult a qualified tax advisor (Steuerberater) for individual advice.

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