Key takeaways

  • The HMRC Construction Industry Scheme helpline number is 0300 200 3210, or +44 161 930 8706 from outside the UK.
  • The CIS helpline is open Monday to Friday, 8am to 6pm, and is closed on bank holidays.
  • For advice on paying CIS deductions, call 0300 200 3200 with your Accounts Office reference; HMRC does not take payments on that line.
  • You cannot register as a CIS subcontractor by phone; HMRC says to register online or by post.
  • Contractors must send CIS monthly returns by the 19th of each month and pay deductions by the 22nd, or the 19th by post.
  • A CIS monthly return filed 1 day late gets a £100 penalty, rising to £200 at 2 months.
  • Since 6 April 2026, HMRC can remove gross payment status at once where a business knew or should have known a payment was connected to fraud.

The HMRC Construction Industry Scheme (CIS) helpline is 0300 200 3210, open Monday to Friday, 8am to 6pm, and closed on bank holidays. It handles general CIS queries, forms and leaflets, and help using CIS online. Questions about paying CIS deductions go to a different number, 0300 200 3200.

Which CIS number should you call?

HMRC uses different lines for general CIS queries, CIS payments and new employers. These are the numbers on GOV.UK, checked on 6 November 2026.

QueryNumberNotes
General CIS enquiries0300 200 3210Forms, CIS online
Paying CIS deductions0300 200 3200Advice only, no payments
New employer support0300 200 3211Includes CIS
Outside the UK (general)+44 161 930 8706Same hours

All lines open Monday to Friday, 8am to 6pm. The CIS payment enquiries page had its phone numbers changed on 29 September 2026, so update any old number you have saved.

For other taxes, see our list of HMRC telephone numbers.

What the CIS helpline can and cannot do

The general line deals with CIS queries for contractors and subcontractors. According to the CIS general enquiries page, it covers:

  • general questions about the Construction Industry Scheme
  • getting CIS forms and leaflets
  • using CIS online

It cannot do two things.

  • Register a subcontractor. You must register online or by post.
  • Hear a penalty appeal. Appeals against a CIS penalty go by post only.

HMRC’s digital assistant gives quick CIS answers and can pass you to an adviser, if one is available.

What to have ready before you call

HMRC asks you to make sure your personal details and address are up to date in your personal tax account, or you may fail security. If you do not have a personal tax account, create one first.

Have these to hand.

  • Your Unique Taxpayer Reference
  • Your Accounts Office reference, for any payment query
  • The tax month the query is about (tax months run from the 6th to the 5th)
  • The subcontractor’s name and UTR, if relevant
  • Any penalty notice or HMRC letter

CIS deadlines contractors must meet

Most CIS calls are about returns, deductions and payments. These are the rules on GOV.UK.

WhatDeadline
Monthly return19th of the month after the tax month ends
Payment and deduction statementsWithin 14 days of the end of the tax month
Pay deductions to HMRC22nd of the month, or 19th by post

For example, the return for the tax month 6 May to 5 June is due by 19 June. If you made no payments, file a nil return or tell HMRC you have temporarily stopped using subcontractors.

CIS deductions are paid with PAYE. If you already have employees, HMRC changes your scheme to a PAYE/CIS scheme and you make one payment covering both. See our HMRC employer helpline guide for PAYE queries.

CIS deduction rates

Contractors deduct one of three rates from a subcontractor’s payment, depending on the subcontractor’s status.

Subcontractor statusDeduction
Registered20%
Not registered30%
Gross payment status0%

Always verify a new subcontractor with HMRC before you pay them, so you know which rate applies.

Penalties for late CIS monthly returns

HMRC charges these penalties for a late monthly return, according to its monthly returns guidance.

How latePenalty
1 day£100
2 months£200
6 months£300 or 5% of deductions, if higher
12 months£300 or 5% of deductions, if higher

After 12 months, HMRC can add a further penalty of up to £3,000 or 100% of the deductions on the return, if higher.

What changed from April 2026?

HMRC’s CIS fraud policy paper, published on 26 November 2025, set out new powers from 6 April 2026. If a business makes or receives a payment it knew or should have known was connected to fraud, HMRC can:

  1. remove its gross payment status immediately
  2. assess the business for the tax lost
  3. charge a 30% penalty, which can fall on the business or its officers

A business that loses gross payment status for fraud or serious non-compliance cannot reapply for 5 years.

Which applies to you?

  • If you are a new subcontractor, register online; you cannot do it by phone.
  • If you are a contractor with a payment question, call 0300 200 3200 with your Accounts Office reference.
  • If you want to appeal a CIS penalty, write to PT Operations, HM Revenue and Customs, BX9 1BX.
  • If you are taking on your first workers, call the new employer line on 0300 200 3211.
  • For anything else, call 0300 200 3210.

Building work may also fall under the VAT domestic reverse charge; see our reverse charge VAT guide. For the quietest times to phone, see the best time to call HMRC.

Frequently asked questions

What is the HMRC CIS helpline number?

The number is 0300 200 3210. From outside the UK, call +44 161 930 8706.

What are the CIS helpline opening hours?

It is open Monday to Friday, 8am to 6pm, and is closed on bank holidays.

Can I register for CIS over the phone?

No. HMRC says you cannot register as a subcontractor by phone; you must register online or by post.

Who do I call about paying CIS deductions?

Call 0300 200 3200 and have your Accounts Office reference ready. HMRC gives advice on that line but does not take payments.

When is the CIS monthly return due?

It is due by the 19th of the month after the tax month ends. A return 1 day late gets a £100 penalty.

Sources

Rates, thresholds and rules in this guide were checked against HMRC and GOV.UK guidance on 6 November 2026. Tax rules change, so check the current position on GOV.UK or with a qualified adviser before acting. This guide is general information, not personal advice.