I won’t go into detail but in our absence we have had some work done in Italy. We had a price and paid some money up front, never a good idea. We were told the worker was an honest man.
When the job was finished we received a photograph of some scribble on a scrap of paper saying how much we owed. It was more than we expected but we assumed the additional 120 euro was tax. We are happy to pay tax for goods and services, transferred the money and asked for an official receipt. This arrived and showed there was no tax, for some reason the work was exempt. Of course we queried the extra 120 euro and were told it was the cost of preparing and issuing the receipt.
Bet you didn’t anticipate that, us neither.