Should companies that perform calibration services be ISO 17025 accredited? Are they required to be? We are an aerospace manufacturer with AS9100 and ISO9001 accreditation requirements. I just found out that our calibration house is not accredited to any calibration standard. We discover this during an internal audit. We have canceled their services. Now we are wondering if everything is questionable and we may have to do an impact to product assessment. Thanks in advance for your comments and suggestions.