Mexico is developing rules that would cap the amount of cash that can used to buy real estate, Finance Minister Carlos Urzua said on Friday, part of a push to reduce the use of physical currency in a country rife with money laundering and corruption.

Urzua, speaking at a banking convention in the resort town of Acapulco, said the government was also considering rules that would require all its payments and collections to be processed electronically.

Also under discussion is the creation of incentives for professionals such as doctors, lawyers and architects to accept electronic payments over cash, he said.

Nearly 57 percent of people in Mexico work off the books, according to government data. Millions lack bank accounts and an estimated 90 percent of all transactions are done in cash.

President Andres Manuel Lopez Obrador, who took office in December, has made it one of his priorities to draw more people into the formal economy and reduce cash in circulation to cut down on the laundering of proceeds from the drug trade and other illicit activities.