Hand luggage on flights - query re bag size?

[LittleManktiesMum]

DH and I are taking the kids away in a few weeks. We've not flown with the DC before and DH and I haven't been on a flight for many, many years!

The carrier we're flying with - Hamburg Int - have a 55x40x20 dimension for hand luggage. My question is this: is this the maximum size of the actual bag or can you take a bigger bag, under-fill it, and so long as it squashes down into this size will this be ok IYSWIM?

Also can I still take a handbag in addition to my hand luggage? If not, what about something like a bum bag?

Many thanks.

Check the airport website for the question about quantity of bags.

The dimensions represent the squash-down size. I have seen so much exceeding of these dimensions, though, that as long as your case fits in the overhead locker, you should be all right.

Thank you for your advice.