Sole traders and landlords keep digital records and submit quarterly updates through compatible software; the annual return remains.
Phases, scope, exceptions & sources →Jurisdiction
United Kingdom
The UK combines serious policy modeling with serious personal tooling: PolicyEngine-UK simulates reforms to the tax and benefit system, while crypto and capital-gains calculators implement HMRC's share-matching rules (same-day, bed-and-breakfast) that generic tools get wrong.
What's missing
Building it? SubmitOpen Making Tax Digital bridging software — MTD mandates digital filing through recognized software, and the recognition process has kept open source out.
4 projects tagged United Kingdom, ranked by community stars.
Tax Prep & Filing · Crypto & Capital GainsActive
BittyTax
BittyTax/BittyTax
Crypto-currency tax calculator with support for all popular wallets, exchanges, explorers and migration from other crypto tax platforms
Crypto & Capital GainsActive
capital-gains-calculator
cgt-calc/capital-gains-calculator
Calculate UK capital gains tax from broker exports for your HMRC Self Assessment
Rules as Code · Policy & MicrosimulationActive
policyengine-uk
PolicyEngine/policyengine-uk
An open-source static tax-benefit microsimulation model for the UK.
Tax Calculators & Engines · Crypto & Capital GainsMaintained
beancount-plugin-tax-uk
Evernight/beancount-plugin-tax-uk
Beancount plugin for generating informational UK tax report (calculate capital gains tax)