Houseshare: Procedure for a tenant replacing themselves with another tenant

My brother is moving into my place next month and leaving the place he's rented with a mate for the past 5 months.

He has another friend who'll take his place on the lease for that rented place, but what's the procedure/notice period and is he likely to lose his deposit, given that he's leaving before the 12 month lease expires?

So to recap! 2 tenants. 1 leaving but has found a replacement tenant. What's the procedure and how should he approach his landlord?

Thanks

When I was housesharing, the new tenant paid the deposit to the one leaving. We never told the landlord,( but there was 4 of us) they were only concerned that they got their money every month. However, given your brother's circumstances, and likely need for a signed tenancy agreement & sorting out of deposits, it would seem advisable to contact the landlord first. He might be a stickler and insist on loss of deposit due to break in lease, but if s/he's reasonable he should be able to negotiate. Only issue might be if damage occurred already, and the new tenant didn't get their deposit back. But maybe a visit from the landlord prior to change-over might overcome this, so that it's a clean handover.

Thanks for that. So the deposit could be in danger? I thought it was possible to replace a tenant name on a lease quite easily with the landlord's agreement. Any more opinions?