The US Department of Transportation has issued Aer Lingus (United Kingdom) (Belfast City) an exemption and, tentatively, a show cause order awarding it a foreign air carrier permit (FACP).

The British subsidiary of Aer Lingus (EI, Dublin Int'l) initially applied for the FACP in December 2020. While the DOT allowed the marketing of flights to be operated by Aer Lingus (UK) under its parent's EI code in March 2021, it deferred the decision on the FACP pending the completion of Aer Lingus (UK)'s certification. The start-up received its UK Air Operator's Certificate in July 2021 and an Operating Licence in early August 2021.

The DOT confirmed in its order that Aer Lingus (UK) remains owned and controlled by citizens of Ireland, including both Aer Lingus as a corporate entity and all but one of its named executives, who are Irish. While such a corporate structure, in principle, runs afoul of US control and ownership requirements, the DOT said that it waived these rules as there was nothing "inimical to US aviation policy or interests" in it.

Aer Lingus (UK) has been authorised to operate flights sold under the codes of its parent and fellow IAG International Airlines Group subsidiary British Airways. The UK start-up intends to launch on October 20 with services to Bridgetown, while its core routes to the US East Coast are due to commence in early December 2021. The airline will not market its flights independently and will, in practice, be a capacity provider to Aer Lingus operating under its code and branding.