to ask a question via posting cards internationally?

[FestiveFruitloop]

Sorry, probably a misuse of AIBU but I'm in a hurry and am posting here for traffic in the hope someone in the know will see this.

Sending Christmas cards out to Republic of Ireland, USA, Canada. This year's the first time I've used Royal Mail's 'pay for postage online and print out labels' service, to save trekking to the Post Office. I've noticed it provides a customs declaration for each label, but as far as I'm aware (and RM website seems to back this up, but wording is a little ambiguous) if it's just a letter/card with nothing else enclosed, there's no need for customs declarations to be attached?

Thanks in advance!

I live overseas and when I receive cards with the print at home stamps, they have a customs label too with "card' written on it.

No idea if my sender is correct printing the customs label too, but that's what she does.

Thanks @RhinosAreJustChubbyUnicorns! Think I might include it just to be on the safe side.

My dad posted me 2 boxes of taytos from the Republic of Ireland last week that had the customs declaration on and their value and he posted cards at the same time that don't have a customs declaration on just a registered post sticker he put all the cards into a little brown envelope and I've just looked it cost as much to send the cards as it did to send two boxes of taytos

I regularly post letters and cards to ROI and have never done a customs label. Its not required but if you want to add it anyway then there's no harm.