The choice of a CAB is important. An accredited CAB (e.g. BSI) should be used wherever possible and with ISO 14001 one won’t be difficult to find.
Accreditation, which is issued by a nationally-recognized Accreditation Board (e.g., UKAS) is an important confirmation as to the legitimacy of the CAB. To help ensure an international ‘level playing field’ for CAB auditing standards National Accreditation Boards have their own international organization, the International Accreditation Forum (IAF), which oversees an ongoing programme of witnessed self-assessment of IAF Members of each others’ activities.
A Certificate from an accredited CAB will carry three logos. #1 the CAB’s own logo and #2 the Accreditation Boards logo and #3 the IAF logo. If you present an ISO 14001 Certificate to a customer or potential customer that does not carry all three logos, expect to be challenged. Without a plausible explanation, you can expect your approach to be rejected.