The 19-year-old forward will join the La Liga giants for €4.5m after they triggered an option to buy him.
Barca paid €1m last March to reserve a first option on Maia and his agents in Brazil say they plan to use it.
As AS explains, Barcelona will receive 70 per cent of the player’s rights for the €4.5m fee.
The remaining 30 per cent will stay with Sao Paulo until 2022.
Barcelona’s option on Maia expires on June 30 and if they don’t sign him before then, they lose their €1m.
A promising talent, Maia was due to be loaned to Flamengo this season, but family problems stopped it.
Subsequently, Maia was suspended by Sao Paulo, which is around the time Barcelona were offered an option to buy him.
Described as ‘very skillful with the ball and technically gifted’, Maia stands 1.69m tall and is yet to play for Sao Paulo’s first team.
If Barcelona do sign him, he will be an investment for the future rather than a first team player.