Contractors or freelancers who see their employment status change under off-payroll (IR35) rules next year will not face an automatic tax probe.
From April 2020, IR35 rules that currently apply to public-sector contractors will be extended to the private sector.
Medium and large-sized organisations that use private-sector contractors will be responsible for determining whether an engagement falls within the rules from this point.
HMRC has addressed concerns among private-sector contractors, who feared a change in employment status would trigger retrospective inquiries.
Instead, the Revenue will only open investigations if it has reason to suspect fraudulent or criminal behaviour from the information it receives.
The clarification has been welcomed by the Association for Tax Technicians (ATT), which praised HMRC's "pragmatic approach".
Jon Stride, co-chair of the ATT's technical steering group, said:
"This is a high bar to clear and builds on earlier statements [from HMRC] that the reforms are not intended to be retrospective.
"Contractors were concerned that recognition of a different status from April 2020 could give HMRC grounds for seeking additional tax for earlier years.
"The risk of any such retrospective inquiry is substantially reduced by HMRC's clarification."
Speak to us about the off-payroll rules.