Do they not offer delivery? I would use their delivery service and see what they suggest to get it upstairs while maintaining the integrity of the mattress etc. This should be something they figure out, in my opinion.

what does the manufacturer say? how is it shipped?

Manufacturer is in England. I'm going to try to get a hold of them. When we were considering a different mattress brand, they said if we order one that doesn't fit up the stairs we are stuck with it and they won't do a refund. It is motivating me to do a lot of research beforehand.

Please check with your manufacturer or find another that has bendable mattresses made for your situation. We bought a Marshall Brand mattress, King Size that was specifically made to bend so it could go up the stairs. We hadn't been able to get a queen size box spring up the stairs so that gives you some idea of how much the mattress bent and squished to get up there. It was a fabulous mattress and we had it for years. I'd buy another without hesitation. The Marshall Brand is Canadian.

NO....do not fold it if it has springs! They will bend PERMENTLY. This happened to us years ago with a very comfortable mattress. It was the movers who actually bent it somehow on their truck. We still have it, but there is a very noticeable bend along the top outer edge of it and there is no way to bend it back into its original shape. Slightly curving it is ok if you have to get it around steps or a sharp corner, but to bend it severely (or try and actually fold it) will cause damage that cannot be undone.

Thanks for your question. I got a regal superb as well and whilst changing the mattress side within the small room I happen to bend the mattress 90 degrees for few seconds, and I was very worried if there is damage to the mattress. Thanks, I found this post, so far there is no visible damage but was still worried