I'm booking a rental cottage in the UK for early September 2024. It's offered by a small independent company with only a few local properties in the portfolio. I'm required to give the names and contact details for all those staying in the property (which sleeps 8) on booking. I phoned them to explain that at the moment I can be sure of 4 names but the other 4 may change nearer the time. I was told that if we planned to have a party of 8 we would need to put down the 8 names and contact details on booking and that there will be a charge if, later, those details change.
Is this standard procedure? It's some years since I booked a holiday rental. I have full, rolling holiday insurance.