Generally, the ISO9001 certificate is valid for 3 years;

　　But the premise is that enterprises must accept the supervision and verification of the certification bodies, that is, annual inspection;

　　Supervision audit frequency is generally once every 12 months, that is, once a year, so called annual review;

　　Some enterprises may be special, and the certification authority requires 6 months or 10 months to require annual inspection;

　　ISO certification audit will notify the time ahead of time, some certification is flight inspection, that is not informed of the inspection, may arrive at the factory unannounced inspection