Prior year losses (SEIS shares) offsetting property CG

Hi, It is possible that I will incur a residential Property capital gain later in the 24/25 tax year, greater than the CGT AEA. I took a loss (not yet registered with HMRC) on an investment in the 22/23 tax year. This was a total loss of SEIS shares when the relevant company went into liquidation. The investment was more than 3 years ago, and at the time I took the 50% allowable investment relief against income tax. Thus leaving me with a 50% loss on company liquidation. I had no CG in either 22/23 or 23/24, so the loss would not be deemed to have been used for offset. Providing I declare the loss, I believe I should be able to use it. Q1 I understand that SEIS losses can be offset against either income or CG. Is that choice at the discretion of the taxpayer ? Q2 If used to offset against income tax, I believe that has to be for either the tax year of the loss, or the prior year ? Is that correct ? Q3 Given the gain is residential property whereas the loss is another asset class, is the loss relief still pound for pound ? i.e. net gain = gain - loss (all other things being equal) i.e. you do not have to adjust pro-rata in accordance with the differential CGT rates for the different asset classes. Q4 When and how do I declare the loss on the prior SEIS investment ? Could I do that immediately, or can/should I wait for completion of my 23/24 Self Assessment return (assuming I file that before I need to complete a CGT return for the property).

Hi,

A SEIS loss can be offset against income or capital gains, at the choice of the individual. You can only set the loss against income in the tax year that the loss arises or the previous tax year. You can carry forward the loss and set it against future capital gains. Losses from other assets, can be set against residential property gains and vice versa.  

You have 4 years from the end of the tax year the loss arises to report the loss to HMRC. If you complete a tax return, you would declare the loss in that and include supporting evidence, or if it is too late to amend your return or you do not need to complete one, you would claim losses in writing and provide supporting evidence of your claim. The address to write to is:

H.M. Revenue and Customs
BX9 1AS

Thank you.