Thousands of employers across the UK are struggling to comply with new statutory record-keeping rules for holiday entitlement and pay, amid warnings that widespread miscalculations could trigger tribunal claims and state penalties.

The compliance burden follows the launch of the Fair Work Agency (FWA), which oversees workplace rights enforcement. Under rules introduced this April, employers must retain detailed annual leave entitlements, holiday pay calculations, and leave histories for six years—aligning statutory holiday records with National Minimum Wage compliance standards.

Failure to maintain adequate records is now a punishable offence, leaving firms exposed to investigations by the FWA, which carries statutory powers to inspect business premises, demand records, and pursue uncapped fines or criminal sanctions.

The operational strain is being felt acutely across the North of England, where industrial, warehousing, and shift-work hubs rely heavily on fluctuating hours and overtime.

The principle of the mandate is simple, but the working reality is complex, according to accountancy and advisory firm Azets.

H-J Dobbie, Head of HR Consultancy at Azets, said: “Typically, HR will deal with holiday entitlement calculations and payroll will deal with holiday pay.

“But with the new onerous responsibility requiring all the data to be in one place and easily accessible, it means HR and payroll will need to work more closely together than ever before."

While holiday calculations for staff on fixed hours and salaries remain standard, compliance breaks down for employees on fixed contracts who earn variable pay through regular overtime, shift allowances, or commissions.

Under statutory rules, employers must apply a 52-week "calendar method" to determine average weekly earnings, requiring payroll teams to review up to 104 weeks of historical pay to capture 52 weeks of actual work.

“The calculation for these workers, based on the ‘calendar method’, is so complicated that employers often don’t know where to start,” Ms Dobbie said.

“What has come to light is that employers do not understand the calendar method or how to calculate holiday pay correctly.

“We are identifying underpayments where workers have not had variable pay components such as regular overtime, shift premiums, etcetera, included in their holiday calculations.

“Employers are in a state of panic as they don’t know how much will be owed to employees when the extent of the underpayments is known, especially as they may have to go back as far as two years to make good with their workers.

“What’s more, they are terrified that the new Fair Work Agency (FWA) will impose hefty fines or open criminal investigations for worker exploitation even though they are trying to do right by staff.”

Government research shows roughly 900,000 UK workers annually have holiday pay withheld, representing £2.1 billion in unpaid remuneration, while nearly 20 per cent of minimum wage workers face wage underpayment.

Ms Dobbie added: “I’m getting calls from bosses of well-run companies worried sick about falling foul of compliance through no fault of their own; they want to ensure staff are paid what they are owed, but the calculation method is so difficult for what appears to be the largest group of workers, that it leaves them exposed, and as of now, we haven’t found two employers tackling this in the same way.

“Bear in mind that holiday pay has to be calculated each time a worker takes leave, so this is not just a one-off annual calculation, rather it has to be carried out multiple times per worker, per year.

“It wouldn’t be an overstatement to say that thousands of businesses, particularly smaller ones without experienced HR and payroll teams, are struggling with the concept of the paperwork that is required to comply.”

With 2.73 million VAT and PAYE-registered businesses operating across the UK economy, payroll specialists warn that fragmented internal systems pose immediate legal hazards.

Julie Gunnell, Associate Director – Growth Payroll at Azets, said: “Many businesses haven’t seen this coming and are not prepared – it’s been like a bolt out of the blue.

“R-Day is a wake-up call. Employers need clear protocols for record access and ownership. If the FWA comes knocking and records are fragmented across HR and payroll, it becomes an admin emergency.

“This legislation is a game-changer - it ensures HR and payroll teams work collaboratively, rather than maintaining separate records, to create a single source of truth.

“Without this alignment, businesses risk compliance failures and potential criminal prosecution for worker exploitation.”