Last updated: March 31, 2026
This policy explains exactly what data Defitax collects, why we collect it, and what we do (and don't do) with it. We tried to keep it short and honest.
When you sign in or add a wallet, we store your public wallet address. This is how we identify your account and fetch your transaction history. We support EVM chains (Ethereum, Base, BSC, Polygon, Arbitrum, Optimism) and Solana. Authentication is via Solana wallet signing.
We fetch your on-chain transaction history from public blockchain APIs (Etherscan for EVM chains, Helius for Solana). This data is already publicly available on the blockchain—we simply organize it. We also store any CEX (centralized exchange) CSV files you upload.
We look up historical token prices from CryptoCompare, CoinGecko, and DexScreener to calculate your cost basis and gains/losses. This price data is cached on our servers but is not personal to you.
Cost basis lots, gain/loss calculations, and generated tax documents are stored on our servers so you can access them across sessions.
If you use the AI Tax Agent, your questions and relevant transaction data are sent to Anthropic's Claude API to generate responses. Wallet addresses are included in the context but no personal identity is attached. Anthropic states they do not use API inputs to train models. Conversation history (last 20 messages) is stored on our servers. You can avoid any data being sent to Anthropic by not using the AI Agent feature.
We record which plan you purchased and for which tax year. Payments are made with USDC on Solana—we store the on-chain transaction signature for verification. No card numbers, billing addresses, or personal financial details are collected.
When you sign in, we derive your country from your IP address for internal quality assurance and to understand which tax jurisdictions to prioritize. We store only the two-letter country code (e.g. "US", "DE") — not your IP address.
We use JWT (JSON Web Token) session tokens stored in your browser to keep you signed in. These expire after 30 days.
Your data is used for one purpose: generating your tax reports.
We do not use your data for advertising, profiling, marketing, or any purpose other than providing the Service to you.
We use the following third-party services to operate Defitax:
We do not share your data with any other third parties. No ad networks, no data brokers, no analytics platforms.
Your data is stored on a dedicated server in Europe. The database is not accessible from the public internet—only the application can reach it. All connections to Defitax are encrypted via HTTPS/TLS.
We take reasonable measures to protect your data, but no system is 100% secure. Since we use wallet-based authentication, the security of your account depends on the security of your wallet.
We keep your data for as long as your account exists. Transaction data and reports are retained so you can reference prior tax years.
If you stop using Defitax, your data sits on our server until you request deletion. We do not actively monitor or process dormant accounts.
You can:
Your on-chain transactions are publicly visible on the blockchain regardless of whether you use Defitax. We do not publish any additional information about your wallet activity. We simply read what is already public and organize it for you.
Defitax is not intended for use by anyone under 18. We do not knowingly collect data from minors.
We may update this Privacy Policy from time to time. Changes will be posted on this page with an updated date. For material changes, we will make reasonable efforts to notify active users.
Questions or concerns about your data? Email contact@defitax.ai.