The six-time Ballon d'Or winner had an agreement in his contract allowing him to walk away for nothing at the end of the current campaign, but had to let the club know before the end of May.
With that time period now having elapsed, the Argentine attacker will spend at least one more season at Camp Nou, where he has won 34 trophies and scored 627 goals in an extraordinary career.
Messi, who will be 33 later this month, is out of contract in 2021 and Barca will now look to start negotiations over a new deal for their star player.
If an agreement cannot be reached by January, Messi would be free to negotiate with other clubs over a possible transfer at the end of the 2020-21 season.
However, the player is happy in Barcelona and not currently considering a move at this point in his career.
Standard Sport understands Messi is likely to sign at least one more contract with the Catalan club.