Bank of Thailand urged all Thais not to mark or write anything on bank notes, to help the country save hundreds of million each year.
In its statement, the central bank said that bank notes are degraded because of the marking and writing and they will be eliminated along with worn-out or torn bank notes.
It said that each year, billions of new bank notes are printed and 80 per cent of them replace the degraded bank notes. The replacement ratio is high compared to other countries'.
A study showed that if people correctly use the bank notes - without marking or tearing, such would help save hundreds of million required for the new note printing, it said.
It also advised all who possess such bank notes to exchange for new ones at Government Savings Bank and commercial banks.