The Bayern Munich president is expected to learn the outcome of his court case Thursday after proceedings started Monday in Bavaria.
The Bayern CEO is accused of failing to pay taxes on an undeclared Swiss bank account and could face time in prison if he is convicted.
Public prosecutor Achim von Engel claimed Hoeness did not fully declare an income totalling 33 million euros earned from 2003 to 2009, leading to a tax evasion of 3.5 million euros divided over seven separate instances.
Hoeness had filed a voluntary disclosure when first charged in 2013 in an attempt to escape prosecution, but this was rejected by the prosecutor on the grounds that his documents were incorrect or incomplete.
The 62-year-old has now conceded that he evaded taxes, confessing to a sum totalling 15 million euros more than Von Engel initially charged him with.
"I will have to make significant tax payments, but I am determined to start with a clean slate. I deeply regret my behavior," Hoeness said in court.
The trial is expected to last four days, meaning Hoeness is likely to learn his fate Thursday.
Hoeness, who won the World Cup as a player in 1974 and has played a pivotal role in re-establishing Bayern as one of Europe's greatest clubs, initially hoped to avoid prosecution after paying back the amounts owed, as German law currently states tax evaders can escape legal proceedings if they turn themselves in prior to the beginning of an investigation.
The allegations sent shockwaves throughout Germany and prompted thousands to pre-emptively pay back taxes in order to avoid possible prosecution, with the number expected to increase over the coming years.