One-fifth of buy-to-let investors and second-home owners failed to pay their capital gains tax on time last year.
New rules were introduced in April 2020 requiring those with taxable gains on residential property to report and pay CGT within 30 days. Under the previous system, they had up to 22 months to do so.
The deadline was extended to 60 days in October 2021 following criticism that the turnaround time was too tight.