On Tuesday, the European Union's finance ministers formally adopted new rules that allow tax authorities to share data on individuals' cryptocurrency holdings. The rules, known as the Eighth Directive on Administrative Cooperation (DAC8), will be published in the EU's Official Journal and come into force 20 days later. The DAC8's crypto provisions complement recently finalized regulations on markets in crypto assets and anti-money laundering rules under the Transfer of Funds Regulation. The rules will require all EU-based crypto-asset service providers, regardless of their size, to report transactions from customers residing in the EU, and will also apply to financial institutions with respect to electronic money and central bank digital currencies.