Error in probate date of death valuation?

For CGT purposes, the acquisition cost of the property is the market value at the date of death.

That means if the house was genuinely worth around £260k on the date of death, that’s the “base cost” you inherit for CGT.

If you sell shortly afterwards for around £270k, the gain is only the difference between the true DOD value and sale proceeds, not the difference between your reported £239k probate figure and sale proceeds.

The figure you put on the probate form is primarily for IHT purposes. Since your mum’s estate was nowhere near the IHT threshold, HMRC aren’t losing any IHT by you having reported £239k rather than £260k.

What matters now is that HMRC could question the probate valuation if they think it was “undervaluing” the estate. That’s why they told you about the C4 corrective form.

Technically, HMRC guidance says you should submit a C4 if the original valuation turns out to be materially wrong — even if no IHT is due. But in practice, HMRC are not usually concerned with correcting small under-valuations when no tax liability changes (i.e., still no IHT due).

The Probate Registry itself told you not to amend unless challenged, which is fairly common advice in no-IHT estates.

Will you get a CGT bill?

If you sell at £270k and HMRC accept that the true DOD value was £260k, your gain is only £10k.

Against that, you can deduct:

Annual CGT exemption (£3,000 for 2025/26, assuming you haven’t used it elsewhere).

Estate agent and solicitor fees. Possibly a share of any other costs associated with sale.

In most cases, that wipes out the “paper gain”. Even if there’s a small gain left, it would be subject to 18% or 24% (depending on your income tax band) on residential property. So the actual tax bill might be negligible.

It is below IHT figure even with the up dated value, so you are stressing over nothing. As it was your mothers main home there is no CGT to Pay provided it is sold out of the estate ownership and you have not transferred it to yourself or another person who may then have it As a 2nd home, in which case CGT may and I say may be payable but not a huge amount.

Reply to the comment left by Neil Patterson at 11/09/2025 – 09:48
Why would you pay CGT on a deceased’s main home being sold out of the estate, regardless of changes in value?

Reply to the comment left by colette at 11/09/2025 – 10:44
Why wouldn’t you?

Reply to the comment left by Olls63 at 11/09/2025 – 11:20
Because you don’t have to🙄

Reply to the comment left by colette at 11/09/2025 – 11:47
Of course you do.
The estate is its own entity, and the fact that it was someone’s home is irrelevant.
If the sale proceeds are greater than the probate value there is a potential for CGT on the estate at 24%.

Reply to the comment left by Olls63 at 11/09/2025 – 12:12
No there isn’t as it was main residence. I’ve just done my aunts estate in same circumstances and no cgt

PRR is only available for Executors when the house was the main residence of at least one individual immediately before and immediately after the death. The individual(s) must also be entitled to at least 75% of the sale proceeds, whether from the Will or otherwise. In practice, therefore, PRR will only be available on death when the deceased was living with someone else.

Reply to the comment left by Olls63 at 11/09/2025 – 16:53
https://www.gov.uk/hmrc-internal-manuals/capital-gains-manual/cg65460

If the house is sold after a death straight from the estate then I believe the probate value is adjusted to the price actually obtained. Since there will be no IHT you don’t need to worry and you can submit the correction form. If you are worried get a surveyor to do a proper valuation (it may be lower than the estate agents, they often are).