Accountants, bankers, lawyers and other advisers who enable offshore tax evasion will face tougher new sanctions from today as part of efforts to create a fair system.
Individuals and corporates who take deliberate action to help others evade tax will be hit with fines of up to 100% of the total they helped evade or £3,000, whichever is highest.
HM Revenue and Customs will also be able to publicly name the tax evasion enabler and charge fines for the first time on those who provide planning, advice or other professional services, or physically move money offshore.
The powers were first announced in the 2015 Budget 2015 and will come into effect today.
Financial Secretary to the Treasury Jane Ellison said: "Tax evasion is a crime and as a Government we have led reform of the international tax system to root it out.
"Closer to home we are creating a tax system where taxes are fair, competitive and paid.
"The raft of measures we have introduced to tackle avoidance and evasion will create a level playing field for the vast majority of people and businesses who play fair and pay what is due."
Shadow Treasury minister Jonathan Reynolds said measures the Government has already taken to try and clamp down on tax avoidance brought in £2.6 billion less than they originally estimated.
The Labour frontbencher said: "The Tories talk the talk but never truly walk the walk when it comes to tackling tax evasion.
"As the OBR (Office for Budget Responsibility) pointed out at the Autumn Statement, three of the Government's flagship anti-avoidance measures are set to bring in £2.6 billion less than the Tories originally claimed. And HMRC blamed its poor performance on underfunding.
"This is equivalent to the cost of employing 12,000 nurses, full-time, every year, for five years.
"Labour would take this issue seriously with our tax transparency enforcement programme, which will make sure that we end the years of Tory failure on tackling tax evasion, and collect the missing billions to help transform and rebuild Britain."