As of 13 August 2026, AI can only partly reduce your Self Assessment tax bill.

What to actually do

1. Hand it to a person

   The route this page recommends

   Someone with a licence or accountable authority has to sign this before it counts.

2. Use a tool built for this

   Second choice

3. Do it yourself

   The distant third

   A chat interface, chat-fluent skill, and roughly 1 hour until you can act on the result.

   How to actually do it

   1. Open your bank and card statements, invoices, receipts, pension records and previous Self Assessment information, then remove account numbers and gather the records for the relevant tax year.
   2. Create a spreadsheet with one row per income item or expense, including the date, amount, description, business or personal purpose, and a link or note showing the supporting evidence.
   3. Paste the spreadsheet summary and your circumstances into the prompt, stating clearly where a figure is missing, estimated or shared between business and personal use.
   4. Ask the chatbot to return a table of possible claims with the rule, evidence needed, uncertainty flag and GOV.UK source, keeping calculations separate from legal conclusions.
   5. Compare every factual figure with your original records and open each GOV.UK source to check that it applies to your tax year and circumstances.
   6. Send the flagged items, source links and supporting records to an accountant or tax adviser before using any uncertain expense or relief on your return.

   Prompt

   Help me identify legitimate ways to reduce my UK Self Assessment tax bill for [tax year]. This is planning and checking support, not permission to claim anything automatically. Use current GOV.UK guidance where available and cite the relevant GOV.UK page for each rule. Separate: 1. facts I supplied, 2. calculations based only on those facts, 3. possible expenses, allowances or reliefs, 4. evidence needed for each item, and 5. questions that need an accountant or tax adviser. Do not invent figures, receipts, dates, business use, eligibility or tax rules. Do not assume an expense is allowable because it is related to work. For every possible claim, state the conditions, limits or exclusions that could prevent it, and mark it CHECK or DO NOT CLAIM where the facts are insufficient. Do not file anything or present an uncertain item as a recommendation. My circumstances and records are: [paste a concise description of your work, income sources, expenses, pension contributions, charitable giving, property or investment income, and any other relevant details]. My documents and figures are: [paste or attach the records, with sensitive account numbers removed].

   Open it prefilled in ChatGPT or Claude, or copy it into Gemini, which takes no prefill link.