Vendor determination during trip posting using PREC/PRFI/PRRW

Hi All,

I have a scenario where employee has been in multiple company code in a particular month and hence has multiple employee vendor. Can some one let me know on which basis vendor will be determined while posting the trip in that month using PREC/PRFI/PRRW as period given in PREC and PRFI is month and year (there is no specific date).

Any input will be helpful.

Thanks,

Priyaranjan