Police are urging people to be vigilant after warning that fake Thai bank notes are in circulation in Phethchaburi and near Bangkok.
The counterfeit 1,000 baht banknotes were found in the Bang Bua Thong area of Nonthaburi.
On Wednesday, police confirmed that counterfeit notes had also been found in circulation in Phetchaburi.
Royal Thai Police spokesman Pol Maj-General Yingyos Thepjamnong said a total of 30 of the counterfeit notes had been found having already been used to pay for goods from local vendors.
Pol Maj-General Yingyos said that by law people who are in possession of counterfeit money are required to hand it in to their nearest police station.
He warned that even people who unwittingly spend counterfeit money in Thailand could face a hefty fine or even jail.
People who use counterfeit money to buy goods face fines of up to 20,000 baht and/or 10 years in jail under Thai law.
People who produce counterfeit money can face between 10 and 20 years in jail and fines of between 20,000 and 40,000 baht.
Meanwhile, National Police chief Pol General Suwat Jaengyodsuk has instructed all police stations nationwide to act promptly in the event counterfeit money surfaces in their vicinity.
Police say the easiest way to tell if a 1,000 baht banknote is real is to check for a vertical metallic strip which is embedded into the note.
When held up the light the note will also display ‘1,000 baht’ written in both Thai and English.
Last year, Hua Hin police released a comparison between a legitimate note and a counterfeit in order to help people more easily spot the fake cash.
Point #1: On a legitimate 1,000 baht bank note, the metal strip is a rich golden yellow colour, compared to the fake where the metal strip has a greenish tint. Also, the metal strip is much closer to the edge of the note on the counterfeit bill.
Point #2: On a legitimate note, the image of the flowers which circle the number ‘1000’ will glisten in the light and will consist of sharp, crisp line. However, on fake notes, the image of the flower does not glisten and the lines are not as sharp or crisp.
Point #3: On a legitimate note, the number 0 of the 1000 on the left-hand side is next to the metal strip. However on the counterfeit note, the zero is much further away.
*article updated to include discovery of notes in Phetchaburi.