Written by the TaxTune Editorial Team·Reviewed by our qualified accountants·Updated June 2026

What has changed

Register by 5 October if you are new to Self Assessment, file a paper return by 31 October, and file online and pay any tax due by 31 January. Missing the online deadline brings an automatic 100 pound penalty even if you owe nothing, with daily penalties after three months.

Who it affects

Anyone who needs to file a Self Assessment return, including the newly self employed, landlords, higher earners and many company directors.

What you should do

Put the dates in your calendar now, and aim to file well before 31 January so you know your bill in advance and can budget. Filing early does not mean paying early.

Our view

Almost every late filing penalty we see was avoidable. Filing early removes the January stress entirely and gives you months to plan for the payment.

Common questions

Who does this affect?
Anyone who needs to file a Self Assessment return, including the newly self employed, landlords, higher earners and many company directors.
What should I do about it?
Put the dates in your calendar now, and aim to file well before 31 January so you know your bill in advance and can budget. Filing early does not mean paying early.
Can TaxTune help me with this?
Yes. Tell us your situation through the quote builder or book a free call, and we will explain exactly what it means for you and handle it if you would like.

Related services and guides

Deadline Centre Self Assessment service Deadlines & penalties guide