The UK has a self-assessment (SA) tax system. As part of this system, most UK taxpayers adjust their tax liability entirely through tax deductions at the source on earnings and savings and do not need to declare any further.
However, one-third of taxpayers are required to complete a tax return, which will be annually declared with the HMRC. Married couples and those living in civil partnerships taxed on their own and are responsible for their own affairs and each files their own return.
Tax returns last date for submission is January 31 after the end of the tax year, and payment of all outstanding taxes. The deadline for filing is October 31 after the end of the tax year for those who would like HMRC to calculate the tax collected for them (although this tax is still due on January 31). The UKSA system moving to fully online, and paper returns now accepted only in limited circumstances.
HMRC recently released a consultation document on simplifying the personal tax system with ideas such as online tax accounts and pre-paid profits.
The deadline for a non-UK resident to notify HMRC of a UK property disposal or interest in a property-rich company is 30 days after the sale completes. If this deadline waives, there will be charges of fines, even if no tax paid. A similar provision introduced for UK residents. From 6 April 2020 in the Capital Gain Tax (CGT) for the disposal of Core residential property.