The Vatican has issued a new rule requiring anyone bringing €10,000 (£8,800) or more into Vatican City to declare it.
The rule went into effect yesterday, on the same day as the Holy See's broader anti-money laundering and anti-terrorist financing regulations became law.
The Vatican announced the measures on 30 December in a major effort to comply with international finance norms and to shed its image as a tax haven with a reputation for secrecy and scandal.
The Vatican's own bank remains implicated in a money-laundering investigation that resulted in ¤23m being seized and its top two officials being placed under investigation last year. The Vatican denies any wrongdoing and says the investigation resulted from a misunderstanding.