Brazil's Central Bank had blocked the service in June 2020, citing concerns about competition in the payment system market.
"Very excited to start enabling Payments in WhatsApp in Brazil today. This will be a gradual roll-out, but enabling people in Brazil to pay one another in conversations as easily as sending a text message is going to be so useful," David Marcus, Head of Facebook Financial, announced in a tweet.
After testing a beta version in India, WhatsApp launched in-app payments in Brazil in June.
While suspending the service, the Central Bank had said it planned to evaluate whether the service was compliant with regulations.
"We know that you were waiting for this. Payments on WhatsApp starts to be available today," WhatsApp said in a tweet.
WhatsApp Pay is also live in India with leading banks for up to 20 million users.
After two years of waiting, Facebook-owned WhatsApp payment service received approval from the National Payments Corporation of India (NPCI) in November to go live on Unified Payment Interface (UPI) with over 160 supported banks.
WhatsApp can expand its UPI user base in a graded manner starting with a maximum registered user base of 20 million.
In another development, consumer protection agencies in Brazil have asked the government to act on the May 15 privacy update that will allow Facebook to aggregate users' data across all of its platforms.