There are several self-assessment deadlines to be aware of:
- The date by which must have registered for self-assessment.
- The date by which you must submit your self-assessment forms.
- The date by which you must pay the tax you owe, along with any Class 2 National Insurance and any payments on account that might be owed.
Depending on the type of income and expenses you need to declare you may need to complete a number of different self assessment forms including the SA103 for your income from self-employment and SA105 for your income from any property.
Once you have completed all the necessary forms it is summarised onto the main self assessment form (SA100).
Some data such as income from the sale of your house must be submitted much earlier than other data (for example your share of any partnership profit or loss).
Each type of tax information has its own rules about when it must be submitted, if you are unsure then you should ask HMRC or an accountant
Additionally, there’s a separate deadline if you wish to fill in your self-assessment form manually and post it to HMRC.
Check these deadlines each year at HMRC’s website. If you miss any, you will be automatically fined.
If you haven’t already registered for self-assessment then you need to do so as soon as possible (you only need to register if it’s the first time you’re making a submission). The basic principle is you must notify HMRC that you are chargeable for income tax within six months from the end of the first tax year for which you are chargeable for tax.
Whatever the case, HMRC’s guidelines say you must register no later than the following:
- Self-employed/sole trader: 5 October in your second year.
- Partners in a partnership: 5 October in your second year.
- Not self-employed: 5 October following the tax year when you earned the money – for this purpose, a tax year is considered to run from 6 April to 5 April.
If you aren’t registered after these dates then you might be penalised.