My tenant wants to move in his brother's family

[ShoutyMom]

We have been letting out our house to a family (husband, wife, baby) ever since we moved overseas last year. The property has been let through an estate agent who fully manage the property as well. The tenancy has been in place for over a year now, no problems at all, regular rent, friendly relations (necessitated by poor response times by estate agent, so tenant has had to escalate maintenance issues to us).
The tenant has now contacted us directly (not through estate agent) asking if he can move his brother's family in for a couple of months while they are looking for a suitable property to buy/rent.
Should I insist on adding the brother to the tenancy contract? Any advice will be gratefully appreciated. So as not to drip feed, I will be asking my estate agent's advice as well, but thought I would tap into MN wisdom as well!

I don't know the legal ramifications but have some thoughts:

You will have two families living in the house - so more wear and tear. Would you like compensation for that? Would there be a problem with the permission to let that your mortgage provider gave , would it be at odds with any conditions they set or contravene your LL insurance in any way?
There might be an issue if your tenants move out and leave the brother's family in situ as you have no contract with them (but AST's are for 6 months minimum so difficult to put them on that) but would have given permission for them to be there. However, perhaps it's fine - your tenants are trying to be honest (they could have not told you), it is their home atm and they are just helping family out temporarily.

I would be concerned this constituted an HMO, effectively two households (and by the sounds of it 4 adults?) would be in the property. I would definitely say no to this.

If the brother's family are just "guests" then I don't think they have any rights (regarding tenancy i.e. they would not be classified as tenants) and so would not be a problem regarding HMO. There may be an issue if the house is very small and them also living there would constitute "statutory overcrowding and/or the house would now be their "primary residence" (so they would not be "guests"). Tenants are allowed to have "guests" come to stay ( but usually cannot sublet/accept rent under their lease/contract).

Wow, so many facets to this that never occurred to me!
Googling AST and HMO :-)
Yes, I do appreciate that they have been honest with me, and not just done it sneakily behind my back, esp since I'm not even in the UK.
House is big enough, it has 4 double bedrooms. So thankfully over-crowding won't be an issue.
Perhaps I can say fine till end of Aug, if it's going to be longer than that we need to add them to the tenancy contract, and also rent would go up by 10%. Does that sound reasonable?

I'd be suspicious of why a family with one do have private rented a house with 4 double bedrooms in the first place. Hmm, gets me thinking this was their plan all along.

Dc not do

Athena, to be honest, we did think about this when they moved in initially. But they passed all background checks and income criteria. Haven't moved the brother's family in even though they have been in there for over a year.

Trying to think of it another way. Why wouldn't they just put all 4 adults on the tenancy contract to begin with (I'm given to understand both brothers have good, stable jobs) rather than this roundabout way.

Not trying to be funny but am wary of pissing off perfectly good tenants unless I have a pretty good reason.

I also think that councils across the country often have different HMO regulations - so you would need to check that out. On thinking about it I think tribot could be right about an HMO problem as presumably the brother's family would no longer have any other residence and so your house would become their "primary residence"

I rent out my old flat and have only had a problem like this once (in 15 years). The tenant allowed relatives to move in (without my knowledge) so that they could claim overcrowding to the council and help get housing priority. When I did find out I asked the tenant to move out with two months notice (on a rolling AST) but was terrified in the meantime that my buildings insurance etc would be invalid if something bad occurred.

Oh ok so I'll also need to check with my insurance provider.

Beware the possibility of creating an HMO so keep the agent involved for their expert advice.