Informal tenancy – can I safely wait before serving formal notice?

Hello everyone, I’m looking for advice about an informal tenancy and whether I can safely wait before serving a formal notice on a property I own in England.

In February 2026, I allowed a friend and her husband to move into my property. My understanding was that this would be very temporary, initially perhaps a few weeks and at most a couple of months, while they were between properties and waiting to move into their new home.

There was no written tenancy agreement, and I did not take a deposit. They have been paying rent and covering the bills. The arrangement was entirely informal.

Their intended house purchase subsequently fell through, and I agreed to let them remain in the property while they sorted things out.

In August 2026, I told my friend that I was considering putting the property on the market. At that point I had not decided on a date for them to leave; I was simply letting them know that I was considering selling.

There was then a discussion about how they might remain in the property for 12 months from the start of the tenancy, together with a proposal that they should have first refusal to buy the property and pay six months’ rent in advance. I did not agree to any of these proposals and subsequently confirmed in writing that I had not agreed to a change to our existing arrangements, a right of first refusal or six months’ rent in advance.

More recently, I spoke to my friend about when they would be able to leave. I told her that I would like them to leave once they had been in the property for 12 months, allowing the appropriate notice period. She said that they would leave by that date. I documented our conversation in an email, but I have not served a formal notice.

I would prefer not to serve a formal notice at this stage if I can avoid it. I would like to give my friend the opportunity to honour what she agreed to, rather than immediately turning the situation into a formal landlord-and-tenant dispute. However, I also don’t want to put myself in a significantly worse legal position by waiting.

My questions are:

– If my friend voluntarily leaves by the date we discussed, is there any problem with continuing informally and not serving a formal notice now?
– If I don’t serve formal notice now and they subsequently change their minds, what would my position be?
– Can I safely wait until later in the year and, if there is no indication that they are making arrangements to move, serve a Ground 1A notice at that point? In particular, would there still be sufficient time to give the required four months’ notice and obtain possession after the 12-month protected period?
– Is there any advantage or disadvantage to serving the Ground 1A notice now, other than the fact that it would make the situation much more formal? I am particularly interested in whether serving now would protect me in a way that I could not achieve by waiting.
– Given that the tenancy began informally in February 2026, there is no written tenancy agreement and no deposit was taken, is there anything I should be doing now to regularise the position?
– If I ultimately need to use Ground 1A because I intend to sell the property, what should I be doing now to make sure I comply with all the requirements?

I would be very grateful for any advice from landlords or legal professionals familiar with the new rules.

Thank you.

Concerned landlord