What it does
BittyTax is a free collection of command-line tools for cryptoasset calculations and data conversion, designed for users familiar with UK crypto taxation. It runs locally, converts exchange and wallet files into a reviewable spreadsheet, then produces a PDF report without a service account.
BittyTax suits a technical workflow built around source files and repeatable command-line processing. Its repository explicitly expects the user to understand cryptoasset taxation rather than treating the tool as an adviser.
Convert, review and calculate
Install the Python package using the instructions for Windows, Mac or Linux. Pass the original exchange or wallet export files to bittytax_conv. It creates BittyTax_Records.xlsx, keeping original rows alongside normalized transactions and using separate sheets for different formats. Unrecognized files are skipped with a warning.
Review that workbook before calculating. A deposit or withdrawal may need a more specific classification, such as income, a gift or a purchase, and missing transactions must be added. Running bittytax BittyTax_Records.xlsx produces BittyTax_Report.pdf. The report includes a yearly calculation, holdings, an audit and an appendix identifying historical price data.
The --audit option adds an Excel log of balance changes for each asset. Negative balances can reveal missing records or chronology problems. --taxyear selects a reporting year, while --debug exposes the calculation in more detail. These controls make it possible to trace an unexpected total back to its inputs.
Cost and scope
The main software uses the AGPL-3.0 licence and has no subscription or transaction cap. Its UK focus is distinct from the separate US branch. BittyTaxAPI also has separate personal-use licensing terms; the main package's licence should not be assumed to cover that service.
Strengths
- Accepts both Excel and CSV transaction records
- The --nopdf option can produce a terminal report without waiting for PDF generation
Watch out for
- Requires command-line use and familiarity with UK cryptoasset taxation
- Imported classifications and missing history need manual review
Best for
- Technical users reconciling exchange exports for UK crypto calculations
- Reviewers who need to trace a report back to individual input rows
Sources
- BittyTax conversion, calculation and audit guide (Oct 27, 2026)
- BittyTax AGPL-3.0 licence (Oct 27, 2026)
- Install BittyTax on desktop systems (Oct 27, 2026)