Former FIFA president Blatter, 86, and Platini, 66, appeared in the Federal Criminal Court in the southern city of Bellinzona, following an investigation that began in 2015 and lasted six years.
They are being tried over a two million Swiss franc ($2.08 million) payment in 2011 to Platini, who was then in charge of European football’s governing body UEFA.
The former French football great “submitted to FIFA in 2011 an allegedly fictitious invoice for a (alleged) debt still existing for his activity as an adviser for FIFA in the years 1998 to 2002,” according to the court.
He and retired Swiss football administrator Blatter could face up to five years in jail.
Both have been accused of fraud and forgery of a document. Blatter is accused of misappropriation and criminal mismanagement, while Platini is accused of participating in those offences.
The trial will conclude on June 22, and the verdict is expected on July 8.