How long do we have before we need to respond to on an offer from a school?

[MissPa]

Hi, yesterday DS was given an offer by the HM of a prep school following an assessment. This is for a spot in Year 4 Sep 2025. We were very excited as we think this school is a great fit for him, and DS also seem to like it very much during his visit!

However, we are also waiting to hear from another school which we like just as much - hopefully in the next 1-2 weeks. My question is: how long do we usually have before we have to give the HM an answer? The HM didn't give us a deadline per se, but we probably shouldn't drag our decision out for too long. Any advice on the whole 'offer acceptance' etiquette would be much appreciated!

Year 4 is a normal entry point for a prep school. I'd ask the second school what they're thinking and say you have an offer somewhere else but are really keen on them.

Not yet but we did ask them for an additional two weeks to think things through as many people have suggested - which they were absolutely okay with. By then it would have been a month since we took the assessment with the other school so hopefully we would hear something from them then - and if not then we will go with this one.

Thank you everyone for helping out!