Tax rules are letting contractors down as they have failed to move with the times, one expert has said.

Office of Tax Simplification tax director John Whiting told Contractor Calculator that systems such as the Pay As You Earn (PAYE) were fine during an era where everyone worked full time, but not those with flexible working timetables.

"Contractors and freelancers are in a halfway house between employees and self-employed tradespeople and professionals," he told the site.

He added that Contractor Calculator had a "very valid point" when they noted that tax legislation has not kept pace with the new workforce that incorporates both flexible and full time workers.

This comes after news that HM Revenues & Customs has vowed to put individuals who avoid paying taxes under increased scrutiny during the next five years as part of their Managing Deliberate Defaulters scheme.