Tenants Separating - need new AST.

Tenancy Types and Management

Hi,

I have a family of four as tenants, the initial 6mth AST (RLA + DepositGuard) is just about to expire (we are already passed the 5th month).

Husband has left and wants to be off the AST, currently he is the lead tenant and Wife & kids are just named as being allowed to live there. Deposit was paid by father too.

They want a new 6mth term in her name and I would like deposit to be "her money" as a nudge to keeping the property in good order.

There have been no major issues and payment is always on time. I believe the She will be able to finance the rent.

So I want to know what the minimum legal requirements are to effectively transfer the tenancy including the deposit to Her.

Does the original lead tenant have to serve formal notice?
How do I ensure that it's the new tenant that has the risk and responsibilities implied by the deposit given that I doubt any money will change hands?

They want to complete this immediately, am I required to insist on the notice period which would mean a seventh months rent under the original agreement, or can we agree to do a faster change over with the new 6mth AST running consecutively with the original one?

Thanks
Bill.