It was recently announced that Canada has joined a five-state coalition of tax authorities, called the "Joint Chiefs of Global Tax Enforcement (J5)", the overall goal of which is to "increase collaboration in the fight against international and transnational tax crime and money laundering." The Canadian government actor involved is, of course, the Canada Revenue Agency. The other partner agencies are the U.S. Internal Revenue Service (not so "internal" any more, I guess), the Australian Criminal Intelligence Commission, the Australian Taxation Office, the Netherlands Fiscale Inlichtingen - en Opsporingsdienst, and the UK's Revenue & Customs.
The IRS webpage on the J5 indicates that it was formed in response to a call from the OECD for states to do more to "tackle enablers of tax crime," and describes the desired results:
The outcome of this active collaboration will see the J5:
- Enhance existing investigation and intelligence programs
- Identify significant targets for new investigations
- Improve the tactical intelligence threat picture now and into the future
- Lead the wider community in developing its strategic understanding of the methods, weaknesses and risks from offshore tax crime and cybercrime
- Raise international awareness that the J5 is working together to reduce transnational tax crime, cybercrime and money laundering, and create uncertainty for those who seek to commit such offenses.
No word yet on whether there is a specific treaty in place to facilitate this collaboration or whether the states will rely on their existing criminal cooperation networks and instruments (extradition, mutual legal assistance, etc.). This is an interesting development in the historical sense, as states have traditionally been loath to engage in much enforcement activity regarding the tax/fiscal laws of other states.