Macau is considering a system requiring travellers to declare the cash they carry across the border.

The enclave is studying a “cross-border cash declaration system, but no timeframe, declaration threshold or penalties are determined yet,” Deborah Ng, director of the city’s Financial Intelligence Office, said.

Any controls imposed by Macau’s government would back China’s currency curbs, which restrict how much money Chinese tourists can take out of the country.

“Such talk may hurt the sentiment on Macau casino stocks,” said one Hong Kong analyst, “but it won’t hurt the casino revenue because there are so many different ways a traveller can get cash in Macau.”

Travellers to Macau currently aren’t required to report how much cash they bring in when entering the city. Tourists from mainland China can bring 20,000 yuan ($3,260) when travelling across the border and withdraw as much as 10,000 yuan a day with each card at cash machines.

High stake gamblers, who contribute about two-thirds of the city’s casino revenue, rely on junket operators for credit to make big bets. To skirt the cap on yuan they can take out of China, gamblers buy expensive goods from pawnshops using debit cards and trade them in for cash at the same store.