Tax – it’s one of those things we all like to grumble about and if you have to file your own, those grumbles are probably echoed by some anxious huffing and puffing as the deadline for submitting them draws ever nearer. But what are the rules on filing your own returns and more importantly – when exactly do they need to be in?

Ok, so first thing’s first, the tax year runs from 6 April until the 5 April the following year. So, a tax return is done after the tax year that it refers to – clear as mud? For example, if you need to do a return for 2015/2016 then you’ll need to start filling it in after 5 April 2016.

The deadlines for sending them in, depend on how you complete your form. If you do your self-assessment online, then you have until 31 January 2017 for the tax year 2015/2016. If you do it old school and on paper, it needed to be posted by 31 October 2016 (might need to start checking out the website…). There was also a deadline of 30 December 2016 if you file your return online and also have earnings that are automatically deducted through PAYE.

Of course, lots of us are employed and have our taxes taken directly from our pay cheques, but that doesn’t mean the rules of self-assessment don’t apply to you. You’ll need to send in a tax return if you:

  • Were self-employed
  • Have £2,500 or more in untaxed income – such as from a rental property, savings or investments
  • Have savings or investments of £10,000 or more before tax
  • Have made profits from selling things like shares or a second home and therefore also pay Capital Gains Tax
  • Were a company director and didn’t get any pay or benefits (the exception is if you work for a charity)
  • Have (or your partner has) an income of more than £50,000 and one of you claimed Child Benefit
  • Have income from abroad that you need to pay tax on; or if you lived abroad and had a UK income
  • Have dividends from shares and you’re a higher rate tax payer
  • Have an income of more than £100,000
  • Were a trustee of a trust or registered pension scheme
  • Had a P800 from HMRC saying you didn’t pay enough tax last year and you haven’t already paid

If you don’t file your tax return by the deadline that applies to you, then you could face a £100 fine if it’s up to three months late; if it’s later than that, then you’ll end up with a bigger fine. Also, don’t forget to actually pay your tax bill (it’s not just about filing them), delays in coughing up will also mean you get slapped with extra charges. So, don’t get caught out like the 870,000 people who sent in their forms late last year.

It’s also worth bearing in mind that if you do need to self-assess and want to submit your forms online; then you’ll have to register with HMRC and this can take time. You’ll get what’s called a ‘unique taxpayer reference’ which is 10 numbers long and then need to wait for an activation code which can take up to seven days.

If you’re the enterprising sort and hold down a job, as well as do freelance work at home, then you can keep your tax bill down by claiming expenses for your freelancing. We’re not talking about thousands of pounds but a few quid here and there for things like heating, electricity and the internet. You can also claim back relief on membership of certain professional organisations that you need to belong to, in order to do your job.

It sounds like a lot to remember, but the page Gov.UK, self-assessment tax returns, has everything you need to know about sorting out your paperwork with the minimal amount of drama.

Of course, if your tax return has left the coffers seriously depleted and you need to find ways of rejuvenating your bank balance, then perhaps now is the time to comparethemarket.com for a better deal on your car, home or pet insurance And while you’re at it, make sure your household’s getting the most for its money and check out whether you could save by switching energy or broadband provider; so let’s start saving…