Depends on the company. Some do 6 month intervals, some do 9 month intervals, at the bare minimum, you'll have to do 12 month intervals.
Some companies might do 12 month recurrent and a one day instrument proficiency check in the sim at the 6th month interval.
Factors to consider are insurance minimums and premiums (does training more often have a pay back in a reduced premium?), crew qualifications (is it more prudent to send your crews more often based on a lack of qualifications/experience?), and corporate culture.