Prosecutors were seeking a two-year sentence for the Paris Saint-Germain player for alleged irregularities related to his transfer to Barcelona five years ago, but the court said on Wednesday a sentence of four to six years could be handed down if Neymar is found guilty.
The decision is a setback for Neymar because in Spain sentences of two years or less for first offences are usually suspended, meaning he would avoid any jail time.
The charges were brought after a Brazilian investment group said it received a smaller compensation because part of Neymar's transfer fee was concealed by those involved.
Neymar's parents, Barcelona president Josep Bartomeu, and former president Sandro Rosell also faced charges, along with Barcelona and Brazilian club Santos.
All parties have denied any wrongdoing and a trial date has not been set.
