As of 13 August 2026, AI can compare UK overdraft interest charges.

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 the current overdraft tariff or account-fee page for each bank you are comparing and copy the relevant rate, fee, charging basis, arranged or unarranged status, account conditions and source link.
   2. Check your bank statements or online banking to record the amount you expect to borrow and the likely number of days, keeping arranged and unarranged borrowing separate.
   3. Paste the copied tariff details and your borrowing assumptions into the prompt, including the date on which each source was checked.
   4. Ask the model to calculate each charge only from the supplied figures and to show the formula, assumptions and source beside every result.
   5. Compare the model's extracted rates and rules against the original bank pages, then correct any misread wording or missing condition in the comparison.
   6. Recalculate the final examples with a calculator and ask your bank to confirm any unclear rate, fee or account condition before switching or borrowing.

   Prompt

   Compare the UK overdraft charges in the information below. Use only the rates, fees, dates and rules I provide or that are quoted in the source links. Do not fill gaps with estimates or remembered rates. If a figure or rule is missing, mark it as unknown.
   
   My comparison date: [DATE]
   Amount I expect to borrow: £[AMOUNT]
   How long I expect to borrow it: [NUMBER OF DAYS]
   Whether the borrowing is arranged or unarranged: [ARRANGED OR UNARRANGED]
   
   Bank and account details:
   [PASTE BANK NAMES, ACCOUNT NAMES, CURRENT RATES, FEES, INTEREST-FREE PERIODS, LIMITS, AND SOURCE LINKS]
   
   For each account:
   1. Extract the relevant rate and fees, quoting the source and the date checked.
   2. State whether the information applies to arranged or unarranged borrowing.
   3. Calculate the estimated charge for my stated amount and period only when the source gives enough information. Show the formula and label assumptions.
   4. Put the accounts in a comparison table, keeping unknown items visible.
   5. Identify which result could change because of a variable rate, account condition, daily calculation, minimum charge or other rule.
   6. Do not recommend a product or give regulated financial advice. End with a checklist of the figures and tariff wording I must confirm with the bank before relying on the comparison.

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