PARTLY

As of 13 August 2026, AI can only partly calculate VAT on your UK quote.

This still needs a person who signs their name to it.

Can you do it?

5 minutesto a draft.

30 minutesto something you’d act on.

Cost, all in£0

Skill needednone

Who has to check ityou

What the alternative costsThe listed AI tools data does not provide a price for a human VAT calculation.

If this goes wrong, you send a quote with the wrong VAT treatment and may need to absorb the difference or issue a correction.

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, no skill needed, and roughly 30 minutes until you can act on the result.

    How to actually do it

    1. Open the quote and your current price list, then copy each line item, quantity, discount and price into a working note.
    2. Check the customer, goods or services, delivery location and VAT treatment against your records, and confirm the VAT rate from GOV.UK or your accountant before using the prompt.
    3. Paste the confirmed rate, treatment and quote figures into the prompt and run it in a chatbot.
    4. Compare the model's net subtotal and VAT total with a calculator, spreadsheet or your quoting software using the same rate.
    5. Check every line against your price list and confirm that discounts, rounding and any zero-rated, exempt or outside-the-scope item have been handled as intended.
    6. Copy the verified breakdown into the quote, save the calculation with the quote record, and send it only after confirming the customer-facing total.

    Prompt

    Calculate the VAT breakdown for this UK quote using only the VAT rate and treatment I supply. Do not guess the VAT rate, whether the sale is standard-rated, zero-rated, exempt or outside the scope of UK VAT, or whether any reverse-charge or place-of-supply rule applies. If any input is missing or uncertain, stop and list the issue for me to check on GOV.UK or with an accountant.

Quote currency: [GBP or other currency]
VAT treatment already confirmed: [describe it]
VAT rate to use: [rate]
Prices before VAT:
[Paste each line item and amount]
Discounts:
[Paste discounts, or write none]

Return:
1. Each line item after any discount.
2. VAT on each line where relevant.
3. The net subtotal.
4. The total VAT, rounded to two decimal places using normal currency rounding.
5. The quote total including VAT.
6. A short list of every assumption and every input I must verify before sending the quote.
Show the formula for each calculation and do not invent missing figures.

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

What it gets wrong

What caps this at PARTLY: judgement under ambiguity, legal accountability and verification cost.

How we scored this

Five axes, each scored nought to two by hand: ten means AI carries the task cleanly, and the thresholds that turn a total into YES, PARTLY or NO are published in the methodology. Each axis name links to its definition.

AxisScore (0–2)
Output2
Inputs1
Verification1
Liability1
Effort delta2
Total7 / 10

The methodology and its thresholds are published in full.

FAQ

Can AI calculate VAT on a quote?
Yes, if you provide the correct VAT rate and the amounts before VAT. It can check the arithmetic and format the breakdown, but you remain responsible for confirming the VAT treatment.
Can ChatGPT add VAT to a quote?
It can add a VAT rate that you supply and calculate the total. Do not ask it to guess the rate or the VAT treatment, and compare its arithmetic with a calculator before sending the quote.
What VAT rate should I use on my UK quote?
That depends on the goods or services, customer, transaction and applicable UK VAT rules. Check the current position on GOV.UK or ask an accountant or tax adviser; this is not professional advice.
Is AI VAT calculation accurate?
The arithmetic can be accurate when the figures and rate are correct, but the model can apply an incorrect assumption without warning. Check the rate and treatment against GOV.UK, and ask an accountant or tax adviser about a serious or unusual case.

Nearby answers

All Proposals & quotes rulings

Assessed by gpt-5.6-luna (gpt-5.6-luna) on 2026-08-13, second-checked by an independent model. Wrong somewhere? Email [email protected] and it gets re-checked.

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