Guernsey, Jersey, and the Isle of Man have finally committed to making records of company ownership public following years of fierce criticism from British MPs that the lack of transparency in the crown dependencies could be aiding money laundering and other financial crimes.

The beneficial ownership registers, which show the ultimate owner of a company, are currently only accessible by local authorities based in the islands. The new plans would see these records being made available to the European Union, businesses, and the general public by 2023.

Starting from 2021, the islands’ registers of beneficial ownership will be merged with their EU equivalents for access by law enforcement authorities, then opened up to financial service businesses that require access for corporate due-diligence purposes, and finally to the public as laid down by the EU’s fifth money laundering directive.

The jurisdictions, part of the United Kingdom and widely regarded by critics as simply tax havens, have been reluctant in the past to open up further, saying they already fulfilled all the necessary legal disclosure requirements put upon them. The islands have also frequently argued that ownership details are already passed to relevant authorities if any request is made and insist that they have always been committed to financial services regulation and transparency.

In a joint statement made by the three islands, Gavin St Pier, chief minister of Guernsey, said that “Guernsey has stated repeatedly that we would move to a public register of beneficial ownership as that becomes an international norm,” while chief minister of the Isle of Man, Howard Quayle, added that “the Isle of Man has a longstanding, and independently verified, track record of meeting international standards.”

While the plans have been largely welcomed by MPs and campaigners, both groups say the plans lack detail and still do not go far enough—and will not be carried out fast enough—to open up company ownership to full scrutiny.

Labour MP Margaret Hodge, who alongside Andrew Mitchell, MP of the governing Conservative Party, led a cross-party group of MPs in March in an attempt to force the islands to make their registers public by 2020, tweeted that while the move signifies “a big step in the right direction for greater transparency,” she still has “concerns over how they will implement truly open public registers and their timeframe.”

Mitchell has said it is unacceptable that banks and accountants—“the very people who devise the schemes exploited by those who trade in dirty money or avoid paying their tax”—should have access to the registers before the public.

Transparency International (TI), meanwhile, said the “devil is in the detail.” “There is currently a lack of clarity as to when they will become public and what form they will take when they do so,” said Duncan Hames, TI’s director of policy. “It is important that this historic announcement is followed by swift action.”

Campaign group Global Witness wrote in a blog that this isn’t a done deal just yet. “The timeframe is long—much longer than European Union Member States will have to play with—and the national action plans they’ve drafted are replete with get-out clauses and there is no detail yet on how the registers will be made public. Moreover, they have given themselves plenty of room to manoeuvre over the next four-plus years by setting out how they will continue to abide by ‘global best practice’ and pay heed to international standards.”