CGT has normally been payable by 31 January after the end of the tax year in which the contracts are exchanged but for residential sales exchanged on or after 6 April 2020 any CGT due will be payable within 30 days of the completion date.
CGT arising on the disposal of assets other than homes will continue to be payable on 31 January where the seller is a UK resident individual or trustee. There are different rules for individuals who live overseas and for corporate sellers.
As well as paying the CGT due you will have to complete a new online CGT return to report the sale within 30 days. We can submit this on your behalf. This is required in addition to your self-assessment tax return which will have to be completed as normal by 31 January for the previous tax year.
If no CGT is payable on the disposal (for example because the gain is fully covered by the private residence exemption or losses or the annual CGT exemption) then you do not have to file the online CGT return.
In effect you will have to report gains from the sale of residential property twice; first on the online CGT return and then on your self-assessment tax return unless, unusually, the self-assessment return for the period is submitted first. There will be penalties for failing to complete either tax return on time so please tell us as soon as you have agreed to sell a residential property.