‘Have I accidentally lost my garage to the next-door neighbour?’

The tone of your email suggests the neighbour who owns the car is still on the scene and paying the monthly fee, but he just does not react or cooperate with any reasonable requests to move his car. So, before they serve notice on him to remove the car, the key thing is for your brother and his wife to be on the right side of the law.

A fundamental legal point is whether the agreement for the neighbour to use the garage created a lease or a licence. We want it to be a licence, because a licence can be revoked at short notice without the occupier (the licensee) having a right to stay on.

A lease is a different beast, which in some circumstances does give to the occupier (the tenant) security to stay on as long as the rent is paid, and also seek to renew the lease at the end of the initial term.

You say in this case nothing is in writing, so we must look at the conduct of the parties, and more particularly what rights they have enjoyed over the past 10 years. The crucial issue is “exclusive occupation”. If the neighbour has locked the garage for the past 10 years and not let your brother and his wife in, this is a scenario akin to a lease. I hope that is not the case.

However, if there has not been exclusive possession, and your brother and his wife also frequently entered the garage without notice – or even better kept some of their own property or possessions in the garage – this is a licence.

If the conduct so far has lent more towards lease than licence, now is the time to bring it back to licence territory, perhaps by your brother and his wife putting some of their belongings in the garage.

In a strange way, the fact there is no written agreement is helpful in that you can now mould what the arrangement is. Though, of course, for the benefit of readers I would always recommend setting up new arrangements like this with a licence agreement.