CGT question - loss on sale from previous year

[d000hg]

Finalising CGT return for the wife and I who sold our jointly owned rental flat (we never lived there) in the 2021/22 tax year. After fees, allowances, etc, we each have taxable gain of ~£8500 and as neither of us attracts HR tax, that's a bill of ~£1500 each.

However, in the 2020/21 tax year I sold my own house I owned 100%, bought in 2006 and lived in until about 2010. I sold it for £2k less than I paid for it. I don't know what fees I paid on the purchase but selling it cost me £1300 in estate agent and solicitor fees so I'm down £3300.
I know you can write off CGT losses from the same or previous years but the gov.uk page has a phrase "only sales which you notified HMRC of" or similar, which I am not fully sure about. As I made a loss, I never did a CGT return for it but I might be misunderstanding.
Is this as simple as saying that in the CGT return for my 50% of the flat, I can put £3300 in as "loss for previous years" and save myself about £600 in tax?

[Paralytic]

What does NLUK's accountant say?

Or ChatGPT, which, in this case, does seem quite helpful (but I'd still not trust it 100%, especially since any tax changes since Sep 2021 will not be included in the model):

I am not a tax professional, but I can provide you with some general information that might be helpful. It's always best to consult with a tax advisor or accountant for specific advice regarding your situation.

Regarding your situation, if you made a loss on the sale of your own house in the 2020/21 tax year, you may be able to use that loss to offset the taxable gain from the sale of the rental flat in the 2021/22 tax year. However, there are a few considerations to keep in mind:

1. Reporting the loss: If you didn't report the loss from the sale of your own house to HMRC, you may need to rectify that situation. Typically, you should report any capital gains or losses on a Self Assessment tax return. If you haven't done so already, you should consider filing an amended return for the 2020/21 tax year to include the loss.
2. Time limit for reporting: There is a time limit for reporting losses from previous tax years. Generally, you have up to four years from the end of the tax year in which the loss occurred to report it. So, if you sold your house in the 2020/21 tax year, you would typically have until the end of the 2024/25 tax year to report the loss.
3. Utilizing the loss: If you report the loss within the allowed time frame, you may be able to use it to offset the taxable gain from the sale of the rental flat. You would need to calculate the net gain for each individual (you and your wife) separately and then apply the loss from your house sale against your portion of the gain. This can help reduce the overall tax liability.

Remember, these are general guidelines, and tax rules can be complex and subject to change. It's important to consult with a qualified tax professional who can review your specific situation and provide personalized advice based on the current tax regulations in your country.

Sounds like you might have to go back and amend your previous self-assessment to report the CGT loss.

[d000hg]

My accountant just responds to questions like this "if you would like us to do your CGT we charge £X00" so I thought I'd ask here as I've basically done the return.

The past sale (loss) wasn't listed on my previous SATR. I've checked and I cannot amend myself through HMRC Online, that is something I can run past the accountant. It sounds like it cannot be retrospectively added to the current year's SATR which would be the easiest.

[d000hg]

All that aside though, loss carried forward is calculated the same as gains - (sale - purchase - costs)? In which case I can put that on the CGT return, amend the 2021/22 SATR and then it all gets tidied up in the 2022/23 SATR which will be filed afterwards.

[Paralytic]

Certainly seems like that (says the random person on the internet who would not be the person in trouble if that was not the case).

[d000hg]

I had figured the property moguls on CUK would know, but AFAIK anything you do wrong on the CGT return you can just amend on your SATR anyway since you have to make estimations.