Kids just got their GCSE results? Here's why you need to tell the taxman

And if you receive child tax credits you need to contact HM Revenue & Customs (HMRC) even if your child ISN'T going into further education or training, to avoid being overpaid and potentially risking having to pay a penalty as a result.

HMRC is urging families to tell it what their teenagers are doing after their GCSEs. It issues this call for action annually, because when 16-year-olds finish their final year of compulsory schooling, the taxman assumes they've left to join the world of work as far as child benefit is concerned - which triggers an end to payments.

To ensure they continue to be paid what they're due for child benefit and tax credits, parents must contact HMRC by Thursday 31 August. Usually a child will need to be studying for A-levels, a vocational qualification or a Government-approved training course for the benefits to continue.

What do I need to do?

If you've a child who's just received their GCSE results, then here's what HMRC says you need to do:

• If you receive child benefit... you need to tell HMRC if your child is continuing their education or training, to avoid your payments stopping after 31 August. (If you miss the 31 August deadline you can still tell HMRC and your payments will be reinstated and backdated for up to three months.)

  If your child isn't continuing their education or training you don't need to tell HMRC as your payments will automatically stop.

• If you receive tax credits... you need to contact HMRC even if your child isn't going into further education or training. If you don't, there's a risk you could be overpaid and have to pay the money back - and HMRC says you may also have to pay a penalty as a result.

How do I contact HMRC?

If your child is aged 16+ and is continuing in full-time education or undertaking an apprenticeship, you can use your online personal tax account to update the details.

If you don't already have a personal tax account, you'll need your national insurance number, a recent payslip or P60 (a passport can be used if you don't have these), and a phone to receive a security access code.

To update HMRC online you need to:

1. Go to your personal tax account and click 'Start now'.

2. Log in or sign up for a Government Gateway account (here's where you'll need the NI number and payslip).

3. Enter the security access code that will be sent to your phone.

4. Update your account with your child's education details.

Alternatively call 0300 200 3100 or send a letter to: Child Tax Credits: Tax Credits Office, Preston, PR1 4AT and/or Child Benefit: Child Benefit Office, PO Box 1, Newcastle Upon Tyne, NE88 1AA.