How to register for the Construction Industry Scheme (CIS)

You must register for the Construction Industry Scheme (CIS) with HM Revenue and Customs (HMRC) if you are a contractor or subcontractor in the construction industry. CIS is a tax deduction scheme where contractors take money from a subcontractor's payments and pay it directly to HMRC. These deductions count as advance payments towards the subcontractor's tax and National Insurance bill. You can register online, and doing so is essential to ensure you comply with the law and that tax is handled correctly.

What is CIS and Who Needs to Register?

The Construction Industry Scheme isn't an extra tax; it's a method of collecting income tax and National Insurance contributions throughout the year from self-employed workers in the construction industry. It helps prevent tax evasion and ensures that tax is paid on time.

You need to register for CIS if you are one of the following:

• A contractor: This is a business that pays subcontractors for construction work. While this includes obvious construction firms, it also applies to businesses that aren't in construction but spend a significant amount on it (e.g., property developers).
• A subcontractor: This is a business that carries out construction work for a contractor. If you are a sole trader, partnership, or limited company doing construction work for a larger firm, you are a subcontractor.

It's very common to be both. For example, if a main contractor hires your plumbing business for a project (making you a subcontractor), and you then pay a self-employed plasterer to help you (making you a contractor), you must register with HMRC as both.

How to Register for CIS

The registration process is different depending on whether you are a subcontractor or a contractor. Before you start, make sure you have your key business information to hand, including your Unique Taxpayer Reference (UTR), National Insurance number, and VAT number (if you have one).

Registering as a Subcontractor

As a sole trader, you typically register for CIS at the same time as you register for Self Assessment. You will be asked if you will be working in the construction industry, and you should confirm this. Once registered, HMRC will process your application and tell you your payment status.

There are two main payment statuses for subcontractors:

• Gross Payment Status: You are paid in full by the contractor with no deductions. To qualify, you must pass three tests set by HMRC: a turnover test, a business test, and a compliance test. This is difficult to achieve as a new business, but you can apply for it later.
• Payment Under Deduction: The contractor deducts tax at the standard rate of 20% from your invoices (minus the cost of materials) and pays it to HMRC on your behalf. This is the default status for most new businesses.

Important: If you are not registered for CIS, contractors are legally required to deduct tax at a higher rate of 30%. This provides a strong incentive to register as soon as you start trading.

Registering as a Contractor

If you will be paying subcontractors, you must register as a contractor. This is a separate process from registering as a subcontractor.

1. You need to register as an 'employer' with HMRC, even if you don't have any direct employees. You can do this online via the GOV.UK website.
2. During the registration, you will be asked if you will be paying subcontractors, which will allow you to add a CIS scheme to your record.
3. Once registered, HMRC will provide you with the details for your contractor scheme. You will then have a legal duty to verify your subcontractors with HMRC, make the correct deductions, and file monthly CIS returns.

Your Responsibilities After Registering

Registration is just the first step. Your ongoing responsibilities are crucial for compliance.

• As a Contractor: You must verify every subcontractor with HMRC before you pay them, make the correct tax deduction (0%, 20%, or 30%), file a CIS return with HMRC every month, and provide each subcontractor with a monthly payment and deduction statement.
• As a Subcontractor: You must keep accurate records of all your income and the CIS deductions made by contractors. When you file your annual Self Assessment tax return, you declare your full income and then claim the CIS deductions as a payment towards your final tax and National Insurance bill.

Top Tips for Managing CIS

• Register Immediately: Don't wait. Getting hit with 30% deductions because you haven't registered can seriously damage your cash flow when you're just starting out.
• Use Accounting Software: Modern accounting software (like Xero, QuickBooks, or Sage) has dedicated CIS features that can automate verifying subcontractors, calculating deductions, and filing monthly returns. This is highly recommended to reduce admin and avoid errors.
• Keep Meticulous Records: Whether it's the deduction statements you receive as a subcontractor or the ones you issue as a contractor, keep everything organised. These documents are essential proof for your tax returns.