Running a construction business comes with enough complexity on the tools — the last thing you need is to fall behind on your tax obligations. The Construction Industry Scheme (CIS) imposes specific reporting and deduction requirements on contractors and subcontractors alike, and the penalties for getting it wrong can be significant. That’s where a specialist CIS accountant makes all the difference.
At H2 Accounting, we work with contractors and construction businesses across England, handling everything from CIS registration and monthly returns to tax refund claims and year-end accounts. Our team — led by a Chartered Accountant qualified with the ICAEW and backed by over 10 years of experience — helps you stay compliant, manage cash flow, and focus on the work that matters most.
What Is the Construction Industry Scheme (CIS)?
The Construction Industry Scheme is a HMRC tax framework that governs how payments are made between contractors and subcontractors in the construction industry. Under CIS, contractors must deduct money from a subcontractor’s payments and pass it directly to HMRC. These deductions count as advance payments towards the subcontractor’s tax and National Insurance bill.
Key facts about CIS:
- Standard deduction rate: 20% for registered subcontractors
- Higher deduction rate: 30% for unregistered subcontractors
- Contractors must submit monthly CIS returns to HMRC, even if no payments were made
- Subcontractors can reclaim overpaid deductions through their Self Assessment or Corporation Tax return
Failing to comply — whether that’s missing a monthly return, making incorrect deductions, or not verifying subcontractors — can result in penalties starting from £100 and escalating quickly.
What Does a CIS Accountant Actually Do?
A CIS accountant manages the full range of compliance and reporting obligations that come with operating under the Construction Industry Scheme. This goes well beyond simply filing returns.
CIS Registration for Contractors and Subcontractors
Before any work begins, both contractors and subcontractors must register with HMRC under CIS. H2 Accounting handles the registration process on your behalf, ensuring it’s done correctly from the start — so you avoid the higher 30% deduction rate and get off on the right foot with HMRC.
Monthly CIS Returns
Contractors are legally required to submit a monthly CIS return, detailing every subcontractor paid during that month. Miss a deadline and HMRC will issue an automatic penalty. H2 Accounting prepares and submits these returns accurately and on time, every month — giving you one less thing to worry about.
Subcontractor Verification
Before making a payment, contractors must verify each subcontractor with HMRC to determine the correct deduction rate. Our team manages this verification process, ensuring you’re never caught out applying the wrong rate.
CIS Tax Refund Claims
Many subcontractors are entitled to a CIS tax refund at the end of the year, particularly if they’ve had 20% or 30% deducted from all their payments. H2 Accounting reviews your records and claims back any overpayments — putting money back in your pocket.
Year-End Accounts and Self Assessment
Beyond CIS-specific compliance, construction businesses still need to file annual accounts and Self Assessment or Corporation Tax returns. Our team handles your full year-end reporting, tying your CIS records into the bigger financial picture.
Why Construction Businesses Choose H2 Accounting
H2 Accounting was built around one principle: making financial management simple, accurate, and stress-free. Our clients across England include sole trader subcontractors, limited company contractors, and growing construction firms — all with different needs, but a shared desire to stay compliant without the headache.
Here’s what sets us apart:
- ICAEW-qualified expertise — our lead accountant brings over a decade of experience, including time at KPMG and cross-sector internal audit work
- Responsive and approachable — we explain complex CIS and tax matters in plain English, so you always know where you stand
- Full-service support — from bookkeeping and payroll to CIS returns and tax planning, everything is handled under one roof
- Serving the whole of England — no matter where your business is based, we can support you remotely and efficiently
Our clients have described H2 Accounting as “professional, friendly, and very clear with explanations” — and that’s exactly the standard we hold ourselves to.
Common CIS Mistakes That Cost Contractors Money
Even experienced contractors can run into trouble with CIS. These are the mistakes we see most often — and help our clients avoid:
- Failing to verify subcontractors before payment — this can result in applying the wrong deduction rate
- Missing monthly return deadlines — HMRC issues automatic penalties even for nil returns
- Incorrect deduction calculations — errors here can trigger compliance checks
- Not reclaiming CIS refunds — many subcontractors leave money on the table by not filing a refund claim
- Treating employees as subcontractors — HMRC scrutinises this closely, and the consequences of getting it wrong are serious
A specialist CIS accountant helps you sidestep all of these pitfalls before they become costly problems.
Frequently Asked Questions About CIS Accounting
What is a CIS accountant, and do I need one?
A CIS accountant is a specialist who manages your obligations under the Construction Industry Scheme — including registration, monthly returns, subcontractor verification, and tax refund claims. If you operate as a contractor or subcontractor in the construction industry in England, working with a CIS accountant significantly reduces your risk of penalties and ensures you’re not overpaying tax.
How much can I claim back as a CIS subcontractor?
The amount you can reclaim depends on your total income, expenses, and the deductions made from your payments throughout the year. If 20% or 30% has been deducted from all your payments, you may be entitled to a substantial refund. H2 Accounting reviews your records and submits the claim on your behalf.
What happens if I miss a monthly CIS return?
HMRC automatically issues a £100 penalty for a late CIS return, even if no payments were made that month. Penalties increase if the return remains outstanding. H2 Accounting manages your monthly returns to ensure deadlines are never missed.
Can H2 Accounting help me if my business is based outside a major city?
Yes. H2 Accounting provides CIS accounting services across the whole of England, working with clients remotely. No matter where your business operates, you can access the same level of expert support.
Get Expert CIS Accounting Support Across England
Whether you’re a sole trader subcontractor navigating CIS for the first time, or an established contractor managing multiple subcontractors each month, H2 Accounting has the expertise to keep your business compliant and your finances in order.
We offer a free 30-minute consultation so you can talk through your situation, ask questions, and find out exactly how we can help — with no obligation to proceed. Call us on +44 7356 246621 to book your free consultation today.
