The Financial Administration said 166 users issued 3,000 receipts with the new system by the afternoon, a fraction of the millions that will be issued on a daily basis once the system is in place.

The new system, an attempt to thwart tax evasion, connects cash registers directly with the revenue service's central IT system, where the receipts are confirmed before they are printed out.

Each receipt gets a unique identifier making it possible for tax inspectors to verify whether the proceeds have been reported.

Stojan Glavač, a senior Financial Administration official, told the STA no problems had been detected on the first day.

A hair salon in Šmarje pri Jelšah that was the first to issue the new receipt likewise said there were no issues.

"It takes an extra second and the receipt is three centimetres longer," an employee told the STA.

Once the system is in place, about 70,000 companies and individuals will use the certified cash registers, which become mandatory for all businesses dealing with cash on 2 January.