From 6 April 2020, when a UK resident sells UK residential property they will only have 30 days to tell HMRC and pay any Capital Gains Tax due. This applies only if tax is due.
When non-UK residents sell either UK residential or non-residential property they will still be required to tell HMRC within 30 days of the sale even if there is no tax to pay. But they will no longer to be able to defer payment via their Self Assessment return.
Further detail can be found here.
