Millions of workers are being urged to double-check how they are paid amid fears they could be sleepwalking into tax avoidance schemes and big penalties.

HMRC has issued a fresh alert after adding another operator to its official list of named tax avoidance schemes, warning that those caught up could face 100% of the tax owed – plus interest and penalties. In a stark message, the tax authority said that while 98%+ of taxpayers comply with the rules, a minority are being lured into arrangements that promise higher take-home pay but ultimately backfire.

Officials warned: “Tax avoidance usually involves artificial transactions that serve no real purpose other than to falsely claim to reduce tax.”

How workers get caught out

The crackdown is focusing heavily on contractors, freelancers and agency staff – particularly those paid through so-called umbrella companies.

These firms often handle payroll, but HMRC says some are being used to disguise tax avoidance schemes.

Workers are being told to look for clear warning signs, including:

• Receiving more money than shown on a payslip
• Being paid via untaxed ‘loans’ or ‘capital advances’
• Complex or unclear pay arrangements that are hard to explain

HMRC stressed that the amount landing in your bank account should 100% match your net pay after tax and National Insurance.

‘You still have to pay’

A key warning is that even if a worker was misled or given poor advice, the responsibility ultimately falls on them. HMRC said: “If you are found using a tax avoidance scheme, you’ll have to pay the tax that is legally due, plus interest. And you may have to pay a penalty.”

Crucially, this comes on top of any fees already paid to the scheme promoter – leaving some victims thousands of pounds out of pocket.

Real-life cases of costly mistakes

HMRC highlighted several cases showing how easily workers can be caught out:

• Chantelle, a nurse, noticed some of her wages were being paid with 0% tax deducted – triggering alarm bells
• Tanya, a single parent, was encouraged into a scheme and later hit with a “large and unexpected tax bill”
• Duncan, an IT manager, signed up to an umbrella company without checking details and ended up in a tax avoidance arrangement

‘Ignoring it will make it worse’

The tax authority is urging anyone who suspects they are involved in a scheme to act quickly. Delays can dramatically increase the amount owed, with HMRC warning: “The longer you leave it the bigger the tax bill.”

Those who come forward may be able to agree instalment plans, helping spread the cost.

What you should do now

Workers are being told to take simple steps to protect themselves:

• Check payslips and contracts carefully
• Avoid schemes promising unusually high take-home pay
• Use HMRC’s tools to verify umbrella companies
• Report suspicious schemes – even anonymously

HMRC added that it is taking a tougher stance by publicly naming avoidance schemes to stop more people falling victim.