Incorrect advice from accountant - WWYD?

[Snog]

Looking for opinions here on what to do next.

I paid for a specialist accountant to calculate my tax on a capital gain.
They advised me of the tax due and asked my to approve the amount so they could upload it to HMRC website.

No calculation was supplied to me just the total tax I owed.

I queried it as it was more than I was expecting and the accountant said sorry she had forgotten to update one of the figures and the correct amount was £1,700 less than she originally said.

I nearly said ok to the original figure as I figured she was a professional and knew what she was doing. I have now asked to see the detailed calculation and it looks right to me.

Given that I nearly paid £1700 in tax that wasn't due to to her mistake would I be reasonable in asking for a discount on the fee (which they made me pay upfront)?

I speak as an accountant in practice on this one.

Normally accountants will charge for the amount of time they spend on something, so in this case I wouldn't charge any time for the correction and re-issue of the tax return, but the original time is "good".

Was your fee based on an original fixed price quote?

If there was an initial quoted fee and you feel the service wasn't good enough (as you say, you'd expect the tax return to be correct in the first place if you'd given them all the information they needed), I personally wouldn't have an issue with giving a reduction as a result of the mistake made.

Many accountants would probably say that you got the service you paid for and nothing incorrect was submitted to HMRC, so the original fee stands, but I'd take a bit more of a pragmatic approach. After all, you might not use us again, but you might recommend us, or, in this case, tell someone NOT to use us if we made a mistake that you don't feel suitably compensated for.

No one actually suffered financial loss so there's that positive.

I would query it and would expect the accountant to be able to tell you how the fee was incurred (number of hours spent, expenses incurred etc.) which you may then wish to dispute.