How do I change my CIS registration details?

If you work in the construction industry as a contractor or subcontractor, your details are held by HMRC under the Construction Industry Scheme (CIS). From time to time, you may need to update your registration details, such as your business address, contact information, trading status, or bank details. Keeping these records up to date ensures you remain compliant and prevents delays with payments or CIS refunds. This article explains how to change your CIS registration details, what information you can update, and how an accountant can help manage the process smoothly.

The Construction Industry Scheme requires contractors and subcontractors to register with HMRC so that tax deductions can be managed correctly. Once registered, your information is stored in HMRC’s CIS database.

If your business circumstances change, you must update HMRC as soon as possible. This helps ensure that CIS payments, deductions, and correspondence are sent to the right place and that your tax record stays accurate.

When to update your CIS registration details

You should update your CIS details whenever there is a change to your personal or business information. Common reasons include:

  • Moving to a new business or home address.

  • Changing your business name or trading style.

  • Updating contact details such as phone numbers or email addresses.

  • Switching bank accounts for payments or refunds.

  • Changing from sole trader to limited company status.

  • Adding or removing partners in a partnership.

  • Ceasing or restarting work in the construction industry.

Failing to update these details can cause problems such as delays in verification, incorrect deduction rates, or HMRC correspondence being sent to the wrong address.

How to change CIS details as a subcontractor

If you are registered as a subcontractor, there are several ways to update your information.

1. Online through your HMRC account

The easiest way to update most CIS details is through your HMRC online account. Once logged in, you can:

  • Change your address or contact details.

  • Update bank information for CIS refunds.

  • Add or remove business partners.

  • Report a change in trading status (for example, from sole trader to limited company).

To do this:

  1. Sign in to your Government Gateway account.

  2. Select the CIS service.

  3. Go to “Manage account” or “Update business details.”

  4. Enter your new information and confirm changes.

HMRC will usually update your records immediately, although some changes may take a few days to appear.

2. By phone

If you prefer, you can contact the HMRC CIS helpline to update your details. The helpline number is available on the GOV.UK website and operates Monday to Friday.

When calling, have the following information ready:

  • Your Unique Taxpayer Reference (UTR).

  • Your National Insurance number (if self employed).

  • Your company name and registration number (if limited).

  • Details of the change you need to make.

HMRC may ask for security information to verify your identity before making any updates.

3. By post

Certain changes, such as switching business structure or adding new company directors, may require written confirmation. You can write to HMRC’s CIS office with your updated details, including your UTR and signature.

Keep a copy of your letter and send it by recorded delivery so you have proof of posting.

How to change CIS details as a contractor

If you are registered as a CIS contractor, you also need to keep your records up to date to ensure your monthly returns and subcontractor verifications remain accurate.

You can update most contractor information in the same way online, by phone, or by post. However, if your company structure changes (for example, you move from sole trader to limited company), you will need to re-register for CIS under the new legal entity.

Re-registering when your business structure changes

Your CIS registration is linked to your Unique Taxpayer Reference. If you change your business structure, you will have a new UTR, which means you must register again for CIS under the new details.

For example:

  • A sole trader incorporating a limited company must register the new company separately for CIS.

  • A partnership that adds or removes partners must inform HMRC and may need a new CIS registration.

An accountant can help manage the transition and ensure that CIS records are transferred correctly to prevent deduction errors or double registration.

Updating your bank details for CIS refunds

If you regularly claim CIS tax refunds, it is important to keep your bank details current. You can update these online through your HMRC account or by contacting the CIS helpline.

To avoid delays, make sure:

  • The new bank account is in the name of your business.

  • All information matches your HMRC records.

  • You notify HMRC before filing your next CIS return or Self Assessment.

Incorrect or outdated bank details can cause HMRC to send your refund by cheque or delay payment altogether.

How accountants help with CIS registration updates

Accountants familiar with the Construction Industry Scheme can manage all updates on your behalf. Their support includes:

  • Notifying HMRC of changes to your business structure or details.

  • Ensuring your CIS records, VAT registration, and PAYE systems are aligned.

  • Updating your payroll and accounting software to reflect the correct details.

  • Checking that your verification and deduction records match the new information.

They also help ensure that changes do not disrupt your CIS payments or refund claims, which is especially important if you are mid-project or have multiple contractors and subcontractors.

Example in practice

A subcontractor changed from self employed to limited company status but forgot to update HMRC. Their contractor continued making CIS deductions under the old UTR, causing confusion and delaying a £3,000 tax refund.

After contacting an accountant, the company was correctly re-registered with CIS, the contractor’s records were updated, and the refund was processed within three weeks.

This example shows how small administrative oversights can cause major delays and how professional support helps resolve issues quickly.

How long it takes to update CIS details

Most CIS updates made online or by phone take effect within a few days. Written requests can take longer, typically two to three weeks, depending on HMRC processing times.

If your changes involve re-registration or a business restructure, it may take several weeks to fully update all tax systems (CIS, VAT, PAYE, and Corporation Tax). An accountant can coordinate these updates to minimise disruption.

Keeping your CIS information accurate

Maintaining up to date CIS records ensures you receive the correct tax treatment and payments. HMRC uses your registration details to verify subcontractors, process deductions, and issue refunds, so even small errors can lead to delays or compliance issues.

You should review your CIS details at least once a year or whenever there is a significant change in your business structure, address, or contact information.

Conclusion

You can change your CIS registration details easily online, by phone, or by post. Keeping your records up to date with HMRC helps avoid delays in payments, refunds, and verifications.

If your business structure changes or you are unsure how to re-register, an accountant can manage the entire process for you, ensuring that all CIS, tax, and payroll records are accurate and compliant. By staying organised and proactive, you can keep your construction business running smoothly without interruptions to your CIS payments or deductions.