This tax form is the main UK personal tax return form and is usually issued to taxpayers in April each year shortly after the tax year end.
The official page for this tax form is on the HMRC website at the link below:
If this link becomes invalid and you spot this before me then please let me know.
If you receive one of these forms - it is a legal document and you are required by law to complete it and return it to HMRC.
If you do not receive this form you may still be required to request and complete one.
The main reasons are: