Thai Smile Airways says if owners of "Child's Angels" don't buy tickets for the popular life-like dolls they will be treated as hand luggage.
Coffee, tea or chucky: A woman lovingly embraces her Child's Angel doll.
The dolls, made to the same proportions as infants, have become fashionable since several celebrities adopted them in the belief they bring good fortune.
The owners take the dolls through a ceremony to draw angels into them in a craze that has swept the country. Believers normally take care of them as their children and dress them up in beautiful outfits.
According to a bulletin issued to the airline's cabin crew members, passengers who come on board with the dolls will be classified into two groups.
For those who do not buy extra plane tickets for their dolls, the items will be regarded as a piece of carry-on baggage with a weight of no more than seven kilogrammes.
The number of Child's Angels taken on board must be documented, while passengers with the dolls will be barred from sitting in exit seats and other seats reserved for those who need special care.
For those who buy extra seats for their dolls, booking staff are instructed to fill in the name “Child's Angel" in the passenger registration, record who their owners are and how many of the dolls they have with them.
Passengers with the dolls will only be allowed to sit in window seats.
According to the guidelines, snacks and drinks will be served to the dolls while seatbelts must be fastened for them during take-off and landing.
The airline on Saturday issued a statement to explain the guideline, which it said was intended to be an internal document.
It said more than 40 passengers had brought their Child's Angel on board over the past two or three months and the guideline was needed for cabin crew staff to deal with them.
Some customers were unhappy when cabin crew members put their dolls in overhead compartments or under the seats, the airline said.
The guideline outlines the procedure for how crew members treat the dolls respectfully while not infringing on the airline's safety requirements.
Thai Smile CEO Woranate Laprabang said most passengers carrying the dolls put the items on their laps or strapped them into the seat next to them, insisting they are valuable. The practice may obstruct or disturb other passengers, he said.
He said the dolls can be put on seats if they are unoccupied, but they must have their seat belts fastened to prevent them from being thrown through the air in the event of turbulence.