The booking sites of some US carriers require an OFAC declaration box be ticked before proceeding with purchasing a ticket. Some don’t.
When I contacted American Airlines about how I could book a ticket from Havana to Miami, and avoid ticking a box about travelling to Cuba - because I am travelling to America - they said I was welcome to make the booking over the phone.
All airlines clearly provide information about OFAC requirements when travelling to Cuba. And it appears that the physical form is only ever asked for once and collected by the airline prior to boarding flights to Cuba.
I simply do not know if travellers flying out of Cuba are asked for OFAC declarations, but will find out in a few months.
Some posters elsewhere suggested the carrier could refuse to board me in Cuba if I did not fill out an OFAC form. Indeed they could, but as I read it the carrier would be in deep doggie doodoo because OFAC only covers those under US jurisdiction. I am not a US citizen, and Havana is not in the USA. OFAC could not require me to fill in an OFAC declaration on landing in Miami, because it only applies if one is under US jurisdiction at the time they propose to travel to Cuba.
Rob - the word control appears in the actual Presidential memorandum even if not in the OFAC FAQ:
" the Secretary of State shall identify the entities or subentities, as appropriate, that are under the control of, or act for or on behalf of, the Cuban military, intelligence, or security services or personnel (such as Grupo de Administracion Empresarial S.A. (GAESA), its affiliates, subsidiaries, and successors), and publish a list of those identified entities and subentities with which direct financial transactions would disproportionately benefit such services or personnel at the expense of the Cuban people or private enterprise in Cuba."
With regard to flying one-way from Cuba to the US, it does not matter what OFAC covers or does not cover - the airline can require an OFAC-style declaration from you and there is nothing you can do to force them to fly you if they don’t want to.
A US airline company is covered by the laws of the USA and those of the State it is headquartered.
Accordingly, if an airline coerced a traveller to sign a document which had no legal force, as a condition of carriage, it would likely open itself to a claim of damages.
So when you said “can require”, it likely meant “coercion”. Acts of coercion are not lawful and cannot be considered something an airline would reasonably require of their travellers.
If an airline chooses not to carry someone from Cuba to the USA they would be wise not to state it was OFAC requirement for a passenger not under US jurisdiction.