Bulgaria has been a member of the European Union for many years and is fully subject to all relevant EU directives, including those on taxation and administrative cooperation (such as ATAD). However, there’s a clear reason why Bulgaria was kept from adopting the Euro for so long: the country lacked a sufficiently credible regulatory and supervisory framework for its banking and financial institutions.
As a result, despite EU membership, Bulgaria retained its national currency, the Lev, which is︀ pegged to the Euro at a nearly fixed exchange rate. This arrangement has allowed Bulgaria︁ to maintain monetary stability while remaining outside the Eurozone.
In this context, I see no︂ compelling reason to expect tax increases simply because Bulgaria may adopt the Euro. Whether a︃ country uses the Euro directly or maintains a currency pegged to it, the implications for︄ monetary policy are largely the same. The adoption of the Euro, in and of itself,︅ is not a meaningful driver of higher taxation. China has a currency (the Chinese yuan)︆ which is pegged to the US dollar, but it doesn't share the same fiscal policy︇ of the United States...