If you are a subcontractor (and you’re not trading through a partnership or limited company) you are self-employed and therefore should be registered for self-assessment. Under self-assessment, you will need to send HM Revenue & Customs (HMRC) a tax return each year.
You should also consider registering for the Construction Industry Scheme (CIS) if you work for a contractor. Under CIS, the contractor will deduct 20% from your payments. If you don’t register for the CIS scheme, the contractor will deduct 30% from your payments instead.
The contractor will pay over the deductions to HMRC and these amounts will count towards your tax and National Insurance bill.
At the end of the tax year (6th April to the following 5th April), you should send HMRC a tax return which shows:
- the full amounts on your invoices as income (or from the statements you’ve had from the contractor)
- any deductions contractors have made in the ‘CIS deductions’ field
HMRC will work out your actual tax and National Insurance bill and then take off the amounts your contractor deducted from you.
If you’re due a tax refund, HMRC will pay the money back.