KUDTAX TOOLS

KudTax Tools & Utilities

Free interactive tools for online sellers, tax advisors, and accountants.

Most usedAccountingActive

E-Commerce Accounting Score: How Good Is Your Accounting?

Assess your e-commerce accounting in 3 minutes: 26 questions, a 0-100 score, risk analysis and concrete actions — free and without sign-up.

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AccountingActive

DATEV Export Validator

Free online tool to validate DATEV EXTF files (ASCII/CSV). Check headers, data row syntax, and field formats before sending to your tax advisor.

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E-CommerceActive

Amazon Fee Calculator

Calculate Amazon FBA fulfillment fees, referral fees, margins, and net profits per product for EU marketplaces.

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TaxActive

VAT Calculator (Gross / Net)

Calculate gross, net, and Value Added Tax (VAT) values instantly for Germany (19% / 7%) and standard EU tax rates.

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TaxActive

EU VAT Number Validator

Check an EU VAT ID against the official format, then query VIES directly: valid, invalid, or no answer from the member state right now.

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AccountingActive

Manual Accounting Cost Calculator

Calculate in seconds how much time and money manual invoice matching really costs your online shop per month and per year.

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E-CommerceActive

E-Commerce Profit & VAT Simulator (OSS)

Simulate your true net profit per sale: platform fees and the VAT of the EU target country (OSS) are deducted automatically.

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THE PRODUCT BEHIND THE TOOLS

Done calculating by hand?

OSS rates, DATEV exports, Amazon fees, invoice matching — everything you check here by hand, kud.tax handles automatically in the background.

Try free for 1 month

Register, confirm your e-mail, get going — you set your account up yourself, right away.

WHY KUDTAX TOOLS?

Free E-Commerce Accounting Tools for Merchants & Tax Advisors

GoBD-Compliant Validation

Compliance with GoBD guidelines is essential when compiling accounting stacks. Our online tools help verify syntax, amounts, and field structures before exporting.

DATEV Interfaces & EXTF Formats

Prevent costly booking errors and tax advisor rejections. Validate DATEV EXTF headers, consultant numbers, and fiscal year constraints directly in browser.

Accurate Fee & Margin Calculations

Calculate Amazon FBA fulfillment costs, referral fees, and unit net profit margins across German, European, and global marketplaces.

100% Local Data Processing

Privacy first: All calculations and file validations run 100% locally inside your web browser. No confidential accounting or customer data is uploaded to external servers.

FREQUENTLY ASKED QUESTIONS

Questions & Answers about the KudTax Tools

Between referral fees, FBA fulfilment charges and storage costs, many sellers only discover on the monthly settlement what a sale really cost them. A fee calculator shows the true per-unit margin before you set a price — so you can tell early whether a supposed bestseller is still profitable once every Amazon cost is deducted, and adjust your fulfilment model or pricing deliberately.

Since July 2021, a single EU-wide threshold of €10,000 per year applies to cross-border B2C sales. Above it, the destination country's VAT is due and must be reported through the OSS scheme. Sellers who keep calculating with domestic rates quietly lose margin in higher-rate countries — or risk back payments. Our profit & VAT simulator runs the numbers per destination country.

Pulling invoices from marketplace portals, matching payments, retyping fee statements, answering your tax advisor's queries: each step looks small on its own, but as order volume grows they add up to a fixed block of work every month. The accounting cost calculator converts your actual time spent into euros per month and year — using your own numbers rather than blanket promises.

Yes — every tool is free to use, with no sign-up required. All calculations and file checks (such as the DATEV EXTF validation) run 100% locally in your browser. No accounting, revenue or customer data is transmitted to any server, so you can safely use the tools with real export files without confidential figures ever leaving your device.

The tools show you the numbers — kud.tax then takes over the recurring work behind them: automatic document matching across marketplaces and payment providers, DATEV-ready exports for your tax advisor, and OSS-ready reporting. You can look around in the product tour without signing up, drive a live demo on sample data for 30 days, or start straight away.