Illicit financial flows (IFFs) have a cross-cutting nature and involve a diversity of crimes and offences transcending tax evasion, such as money laundering, terrorism financing and corruption. It is thus highly important for jurisdictions to adopt a whole-of-government approach to addressing them, notably through the sharing of information from tax to nontax authorities, which can include information exchanged under international tax agreements. This latter process is also known as the “wider use of treaty-exchanged information”. Wider use is envisaged by various international tax agreements, bilateral and multilateral, provided that certain conditions are met, usually where a similar use for non-tax purposes is allowed at the domestic level in both collaborating jurisdictions and where prior authorisation is granted by the jurisdiction providing the information. While several jurisdictions are interested in developing this form of co-operation as part of their whole-of-government approach to fighting IFFs, in practice they face operational challenges in implementing wider use, in particular with respect to the need to obtain consent from the jurisdiction providing the information.