What Is an Air Operator Certificate?

How it works

An Air Operator Certificate is the document that confirms a company is fit to fly paying passengers or cargo commercially. It is issued to the operator, not to a pilot or to an aircraft, and it covers the whole operation: the fleet, the maintenance arrangements, the crew training and licensing, the operations manual and the safety management system.

In the UK, the Civil Aviation Authority issues the AOC, under the Air Navigation Order 2016 and retained EU aviation law. In EU member states, the national aviation authority issues it under EASA's air operations rules, principally Regulation (EU) No 965/2012. This describes the position as it stood on 28 September 2026; the underlying regulations are amended from time to time.

The United States does not use the term AOC. The FAA issues a certificate under 14 CFR Part 119, with operations specifications that authorise a company to fly under 14 CFR Part 135 (on-demand charter) or 14 CFR Part 121 (scheduled airline service). This certificate is the US counterpart of an AOC, and this glossary's Part 91 vs Part 135 entry describes it in that context, but it is not itself called an Air Operator Certificate; AOC is the ICAO term used by the UK CAA and by EASA member states.

A charter broker is a different party from an operator and does not hold an AOC or a Part 135 certificate; the glossary's Charter Broker vs Operator entry sets out that distinction. Whoever holds operational control of a flight is the party whose certificate covers it. Under a dry lease the lessee usually operates under its own AOC or equivalent certificate; under a wet lease the lessor keeps operational control and the flight is flown under the lessor's certificate, as described in the Dry Lease vs Wet Lease entry.

Holding an AOC involves ongoing oversight: the issuing authority audits the operator's safety systems, maintenance records and crew competency on a recurring basis, and can suspend or revoke the certificate. A flight conducted commercially without a valid certificate covering it, or outside the terms of that certificate, is sometimes described in the industry as a grey charter, a term this glossary defines separately.

Cost impact

An AOC is not a line on a charter invoice; a charter client never pays an AOC fee directly. Its effect on price is indirect, running through the cost of compliance that a certificated operator carries and recovers in its hourly rates.

Obtaining and keeping an AOC means the operator funds a safety management system, recurrent crew training, an accountable manager, scheduled internal and regulatory audits, and the record-keeping these require. These are fixed costs spread across the operator's flying hours, so they sit inside the hourly rate a client is quoted rather than appearing as a separate charge.

To size this illustratively: suppose an operator's certificate-related compliance costs run to an illustrative £400,000 a year, spread across an illustrative 2,000 flight hours across its fleet. That is an illustrative £200 per flight hour built into pricing before fuel, crew and other direct costs are added. An operator flying without a valid certificate, or outside its scope, avoids this cost and can quote materially lower, which is part of how grey charter pricing undercuts certificated operators; the client bears the legal and safety risk of that gap rather than the cost saving it might appear to be.

The practical effect for a charter client, in either the UK under the CAA or in an EU state under its national authority, is that a valid AOC is what makes an operator's insurance, liability position and regulatory oversight apply to the flight at all. A US client checking an operator's Part 135 certificate under the FAA's Part 119 rules is doing the equivalent check, using different terminology.

Example

Suppose, for illustration, a broker in the UK quotes two operators for the same one-hour charter flight. Operator A holds a valid UK CAA Air Operator Certificate, carries the associated insurance and safety oversight, and quotes an illustrative £3,000. Operator B is flying commercially without a valid certificate covering the flight, avoids those compliance costs, and quotes an illustrative £2,200.

The illustrative £800 difference is not a discount in the ordinary sense; it broadly reflects the cost of the audited safety systems, training and insurance that Operator A's certificate requires and Operator B has not funded. A client booking with Operator B, for this illustrative £800 saving, is accepting a flight that falls outside the CAA's oversight of that operator, which is the situation the term grey charter describes. The AOC itself carries no separate fee, but it is the reason one quote and the other differ.