Our registration paperwork got lost in the mail! I was really worried about what would happen so I rang them and they said just to get a new lot of paperwork (luckily MIL is a midwife and did this for me) and write a letter about what had happened. No problem at all. We got her certificate in the mail not long after I sent the paperwork off. Different situation but just wanted to say they are very understanding. I would pop it in an express envelope like others said just for your peace of mind but I don't think they will care.