Thank you for the question. It is my pleasure to help you with this today. Please bear with me if I ask for more information.
it comes down to what facilities you share with this friend. If you share the kitchen, bathroom or living room, then you are an excluded occupier and either of you can end the tenancy on reasonable notice.
If you don’t share any living space, but simply use your own room you are a lodger/ non-excluded tenant and she cannot evict you without a court order unless you leave voluntarily. In the case of an excluded tenancy (if you share facilities), the notice required is one week. If you paid rent weekly or one month iIf you pay monthly.
An excluded tenant who does not move out at the end of the period can be locked out. The notice period for a non-excluded tenancy (lodger) is the same, although a non-excluded tenancy (lodger) cannot be locked out if they don’t move out.
The notice required in either case by the tenant/lodger is the same as the rental period. One month for monthly rent and one week for weekly rent. Here is the government website which explains.
So, regardless of what it is, from the facts you have given me, you can simply give one months notice to quit and leave.
There is no requirement for you to pay any deposit and by the same token, there is no need for it to go into any scheme. if you do pay one. You are not on the tenancy agreement, you have not signed anything and therefore you do not have to stay until the end of the term.
Does that answer the question? Can I help further?