pretty much what everyone else has said. I remember having mum and DH chase up RSVP's for our wedding. Tended to be people like DH's siblings who didn't RSVP, apparently we are supposed to automatically know who is coming or not. We got to a week or two before the wedding and I just told everyone that if they didn't tell me they were coming by now, Then we would be assuming they wouldn't be there. Even worse were those people who decided to rsvp for themselves and 'others who weren't on the invitation in the first place' ! My family / side was the worst for this - unless the invitation specifies 'guest' you are not entitled to bring one! If you really want someone else to attend with you, talk to the host and ask if it is alright - DO NOT JUST ASSUME!