I haven't used them in ages. Does anyone know if they need to see the credit card used for an online booking when checking in for the flight?

Thanks,

NL

The many times that I have flew with them, not once did they ask for a show of credit card used for booking the tickets. If you are worried about showing a credit card at check in, you can even pay for the tickets at any 7/11 store. The fee is much lower than paying with a credit card.

You can also check-in online and print your boarding passes up to 14 days in advance of the flight. (Except when flying on AirAsia X.)

Same experience here. I have never been asked by AA to show a credit card at checkin. These days, I check in online anyway and go straight through. But I once got caught out by Bangkok Airways, which does ask to see a credit card and will not let, for example, your GF fly without you on a ticket you bought for her on your credit card. To do that, you have to visit their office, where using your credit card to buy her the exact same ticket is perfectly OK. Utterly absurd, but true. That and the fact unlike with AA, you can only check in 24 hours before flying in both directions (meaning two separate operations, both at the last minute), the stodgy, sugary food they serve in their lounges and on their flights, and the extortionate fares they charge on routes where they have a near-monopoly (most notoriously BKK-Koh Samui) are three good reasons never to use that airline.

Have been showing my CC's for years but happened to ask the Thai Smile check in lady yesterday and she said CC's not necessary any more

No they don't but, if possible, take it in case there is a problem.

I have been caught out with this in the past.

No they don't. It is not part of their requirements. You can also book a ticket online for a third person using your own credit card and there is no problem at the check in if you are not with the person during the check in. I am doing that many times