As a UK resident, you’re only required to report gains on UK residential property where tax is due (opposed to non-UK residents have been required to report a disposal on a UK residential property since 6 April 2015, even if there is no UK tax due). In most cases, you’ll be able to exempt the capital gain using Principal Private Resident Relief (PPR relief).
PPR relief provides an exemption for the period of ownership and occupation. In addition, the final period of ownership can be relieved as long as you have occupied the property as your main residence at some point in the period of ownership. From 6 April 2020, this final period of ownership has been reduced from 18 months to 9 months.
In addition to PPR relief, you could claim lettings relief if you rented out the property. From 6 April 2020, this relief now only applies where you (the owner) occupied the property as your main home alongside the tenant.