To be confused about postage (cards "may require extra postage")

[AliceinBunniland]

I got a box of hand crafted cards from Costco, the kind with bits stuck on, each one different, and have just realised they all say "may require extra postage".

I read online a first class stamp covers up to 100g and the cards I have weighed (the ones that look heaviest) weigh around 35-40g.

Some of them are a little bulky but not massively. If they are not hugely thick would you assume a standard 1st or 2nd class stamp is fine?

I agree. I think it's nonsense. I've been buying Costco Christmas cards for 20 years, and none of them are that heavy, and they all fit through a letter box size, which is the measure of Royal Mail.

If I’m ever u sure or thing a card feels a bit heavy, I just stick 2 stamps on.

Thanks everyone

I am going to go to the PO tomorrow. I'll take the the stamps with me but not put any one until they have weighed them in case any need extra postage.

I have a couple of parcels to send anyway so I will wrap those tonight and take them all together.

@AliceinBunniland

Thanks everyone

I am going to go to the PO tomorrow. I'll take the the stamps with me but not put any one until they have weighed them in case any need extra postage.

I have a couple of parcels to send anyway so I will wrap those tonight and take them all together.

The weight won't be an issue. It's the thickness which determines the cost of sending as a letter.

Yeah sorry I meant check the thickness too

I can weigh them myself

It'll be a thickness thing not weight, a friend of ours posted all her lovely handmade wedding invitations only for every single one of them to get seized for excess thickness, all her guests had to pay £1.55 to receive them. She was mortified.

I have found that if you don't pay they eventually deliver it anyway... (We received a postcard about 8 months after it was posted without a stamp) Probably not something to rely on though!

@Oblomov20

I agree. I think it's nonsense. I've been buying Costco Christmas cards for 20 years, and none of them are that heavy, and they all fit through a letter box size, which is the measure of Royal Mail.

Standard letter is much smaller than a letter box: 5mm thick/deep and 165mm x 240mm

Large letter is 25 mm thick/deep and 250mm x 353mm

Standard door letterboxes will fit the 250mm width but are taller/deeper then both standard and large letter at about 2.5” to 3”, (approx 65mm to 80cm) More than double the thickness of large letter

@Oblomov20

I agree. I think it's nonsense. I've been buying Costco Christmas cards for 20 years, and none of them are that heavy, and they all fit through a letter box size, which is the measure of Royal Mail.

Of course a card will fit through a letter box, that's not the issue here! The issue is that a standard letter has to be a maximum of 5mm thick, anything more and it is classed as a large letter and will cost more to send. That's what is relevant to the OP.