Hoeness, 62, would face a possible jail term if found guilty by the court in the southern city of Munich, which has scheduled a four-day trial with a verdict expected on Thursday.
The veteran footballer has admitted to having long hidden money from the German taxman, but says he went clean with authorities by filing a declaration in January last year.
At issue in the trial at Munich's higher regional court will be whether his declaration was valid and guarantees him immunity from prosecution.
Prosecutors are expected to argue that the self-reporting contained irregularities and is invalid because authorities already had Hoeness in their crosshairs at the time.
Under German law, the charges against him have not been publicly released until the start of the trial.
According to media reports, he stands accused of having evaded €3.5 million ($4.8 million) in taxes over seven years, with prosecutors levelling one charge for each fiscal year.
Hoeness has stayed on so far as president of the European champions club, amid expressions of loyalty from fans, players and corporate sponsors such as Adidas, Audi, VW and Deutsche Telekom.
But a conviction would likely spell the end of his illustrious football career and possibly a stint in jail, the usual punishment in Germany for tax evasion above one million euros.
Hoeness has spent more than four decades with the Bavarian sporting giants — first as player, helping win then West Germany the 1974 World Cup, then as team manager and, since 2009, as club president.
The maximum punishment for major tax fraud is 10 years jail, but shorter terms which can be suspended are far more common.
Public interest in the case has been intense — the 49 allocated media spots to cover the trial were filled within 27 seconds, the court said.