Higher preference automatically accepted?

[DSDSDD]

In the event that you receive an offer for a higher preference school, having already accepted a lower preference offer:

a) are you under any obligation to accept the new/higher preference offer? or
b) is the higher offer automatically accepted and the lower offer (which has already been accepted and acknowledged by the local authority), cancelled/withdrawn?

[mitasol]

It depends on the policy of your LA. Some permit you to choose and others will automatically withdraw the lower preference school and allocate the higher preference school.

If the application is for schools outside your LA you need to understand how they will handle your application too.