As of 13 August 2026, AI can only partly claim mileage expenses on your tax return.

What to actually do

1. Hand it to a person

   The route this page recommends

   A person who owns the outcome does this end to end, worth it when the failure is dear.

2. Use a tool built for this

   Second choice

3. Do it yourself

   The distant third

   A chat interface, chat-fluent skill, and roughly 30 minutes until you can act on the result.

   How to actually do it

   1. Open GOV.UK guidance on employment expenses and mileage claims, and separately note whether you are completing an employee claim or a Self Assessment return as a sole trader.
   2. Gather your mileage log, vehicle type, business purpose for each journey, dates, mileage, commuting details and any mileage payments or reimbursements received.
   3. Remove journeys that are clearly private or ordinary commuting, but keep any uncertain journeys marked for checking rather than deciding them yourself.
   4. Paste the prompt and your cleaned mileage log into a chatbot, including the tax year and whether you are an employee or sole trader.
   5. Compare the model's calculations with your mileage log and compare its cited rules and rates with the GOV.UK pages you opened.
   6. Enter only figures and journeys that you can support in your tax-return software, and save the mileage log, receipts and payment records with your tax papers.
   7. Ask an accountant or tax adviser to check the claim before submission if your travel pattern, reimbursement, employment status or vehicle treatment is unclear.

   Prompt

   Help me prepare a UK mileage-expense claim for my tax return. This is preparation only, not filing and not professional advice.
   
   First establish whether I am an employee or a sole trader, whether I receive any mileage allowance or reimbursement, which tax year applies, and whether the journeys were wholly for business rather than ordinary commuting. If any answer is missing, ask me for it before calculating.
   
   Use only the information I provide and current official GOV.UK guidance. Do not invent mileage, rates, allowances, dates, vehicle details or eligibility. Do not assume that every journey qualifies. Separate:
   1. journeys and mileage that may qualify,
   2. journeys or amounts that need checking,
   3. personal or commuting journeys that should not be included,
   4. mileage payments already received, and
   5. information still missing.
   
   For this data:
   Tax year: [tax year]
   Status: [employee or sole trader]
   Vehicle type: [car, van, motorcycle, bicycle or other]
   Mileage payments received: [amount and payer, or none]
   Mileage log:
   [date | start and end points | business purpose | business miles | notes about commuting or private use]
   
   Produce a table showing each journey, whether it appears potentially allowable, the reason, and any issue to check. Then calculate the total business mileage and show the arithmetic without rounding away the underlying mileage. If the correct tax treatment depends on facts or a rule you cannot confirm, say so clearly instead of guessing. Give me the relevant GOV.UK page links to check, identify the boxes or sections I should discuss with the tax-return software or an accountant, and finish with a short list of records I should retain. Do not submit a return or tell me that I am definitely entitled to claim.

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