For customers subject to audits we suggest that they be calibrated/certified on a yearly cycle. This is mainly due to the certification being dated with a yearly expiration. Typically a dated sticker is placed on the instrument as well.
For customers not subject to audits we suggest every other year calibration cycle.
Fluke meters come calibrated from the factory but the calibration is not Certified to a traceable standard. It will meet the accuracy specifications stated in the users manual.