CIS accountant in Harrow: file your CIS tax return and claim your CIS refund

Every subcontractor paid under CIS must file a self assessment tax return each year to reclaim the tax deducted at source. If you are a sole trader bricklayer, plumber, electrician, roofer, plasterer, carpenter, groundworker, scaffolder, painter, decorator, labourer or any other trade paid under CIS, we prepare and file your SA100 with the full CIS suffered figure, claim every allowable expense (tools, PPE, mileage, van, phone, insurance, protective clothing, subsistence, subscriptions, use of home), and turn your CIS deductions into a real cash refund from HMRC. Bring your CIS statements (or your bank statements if the contractor never issued any) and we will do the rest.

If a contractor deducted 20% CIS on your labour (or 30% because you were not verified), that money is sitting with HMRC waiting for you to claim it back. Most self employed subcontractors are due a CIS tax refund of £2,000 to £8,000 per tax year once allowable expenses are properly claimed. We calculate your net profit, apply your personal allowance (£12,570 for 2026/27), offset the CIS already suffered, and file the SA100 and SA103S. If a refund is due, HMRC normally pays it into your bank within 4 to 8 weeks of submission. We chase HMRC directly if anything drifts.

If you trade through a limited company and contractors deduct CIS from your invoices, the deduction is not lost. Each month we report your CIS suffered through the RTI Employer Payment Summary (EPS), and HMRC offsets it against your company's PAYE, NIC and CIS liabilities. Where the CIS suffered exceeds what you owe, we submit a written repayment claim after the tax year ends (from 6 April) and secure a cash refund to the company bank account. Getting the EPS wrong is the single biggest reason Ltd subcontractors lose money to CIS. We fix historic errors going back four years.

Every month we collect your subcontractor invoices, verify each subbie with HMRC (20% standard, 30% unverified or 0% gross payment status), prepare and file the monthly CIS300 return, issue the payment and deduction statement to each subcontractor, and remind you of the 22nd payment deadline. Late CIS filing triggers an automatic £100 penalty on day one, £200 at two months, then 5% of deductions or £300 (whichever is higher) at six and twelve months. We make sure that never happens.

Gross payment status (GPS) means contractors pay you the full invoice with zero CIS deducted, transforming your cashflow. To qualify you need a clean HMRC compliance record, to pass the business test, and turnover above £30,000 (sole trader), £30,000 per director (Ltd company), or £100,000 total (Ltd). We audit your compliance history first, fix any late VAT, PAYE or self assessment issues, prepare and submit the GPS application, and defend the annual Tax Treatment Qualification Test (TTQT) if HMRC threatens to withdraw the status.

Since March 2021 most B2B construction services fall under the domestic reverse charge (DRC) for VAT. If you are VAT registered and supply another VAT and CIS registered business, you invoice with no VAT and the customer accounts for it. Getting this wrong causes cashflow disasters and VAT assessments. We set up your accounting software (Xero, QuickBooks, FreeAgent, Sage) to apply the DRC correctly on every invoice, and reconcile your VAT return each quarter under Making Tax Digital.