Tenant wants her daughter to move in

My BTL mortgage policy just states 'students/professionals' for example and doesn't stipulate the number of occupants allowed... So I'd just look at what the policy states.
We never object to another adult moving in this sort of scenario, although we have had a case where the adult (druggy) daughter and her partner moved in and the tenant went off to Barcelona to live and said to us 'talk to her. I don't live there anymore!' We of course said we would only liaise with him but it took a few months to get her out and we were owed a few months of rent which we never got back. Similarly we had a working tenant who moved in an unemployed friend and then left the latter in situ. But we negotiated with the unemployed one and he became the tenant.... I wouldn't worry at all about the situation here though, as your tenants are unlikely to move out and leave just the daughter there, I presume and even if they did, as I say, there can also be a solution then. Worry when you need to is the motto I am trying to adopt in life. All the best.

hmmmmmmmm, warning - horror story following:
We had a middle aged female tenant (and since moving in she had started to work part time due to 'ill health' and so received a contribution to her rent from the local council) a few years back. She was renting our tiny bungalow (just 3 rooms - lounge, kitchen and ensuite bedroom) and asked could her daughter stay with her for 'a little while' and sleep on the sofa in the lounge while she sought her own accommodation in the area (so she could move nearer to her 'dear old mum') We, being the sweetie pies that we are, agreed.
Up until that point, so for maybe 2 years, said lady had been a reasonable tenant whose rent was paid on time and who had passed our 6 monthly landlord inspections.
Fast forward 6 months and we receive a call from the tenant to say her boiler had failed.
While waiting for our engineer to attend (we explained to the tenant there would be a delay of 3 days because he was on a course but we dropped off 2 stand alone heaters to keep her warm in the interim), we received a call from the local council on the 3rd day telling us that we were to have the boiler fixed immediately and as a matter of urgency due to there being a '6 week old baby living in the property'!!!

Soooo.... the engineer arrived to fix the boiler on the 3rd day (as arranged), and reported back to us that the 'guest' daughter was still living in the bungalow - along with her 6 week old baby, her adult male partner, a cat + 5 dogs (and a litter of puppies)!!!
So now we had 3 adults, a baby + 6 animals and a litter of puppies all residing in our tiny one bed property!
Needless to say (with the support of the same council official the tenant had involved to beat us up over a 3 day delay) they were all - eventually - evicted, but the cost of that in terms of stress and the damage caused by the animals (and a tenant who had clearly lost her grip on reality) was horrendous - and of course the deposit hardly touched the sides of that cost (especially when the lovely tenant failed to pay her last months rent as a parting gesture).

Reply to the comment left by "Denise D" at "13/09/2014 - 09:36":

Yet another incidence of the "revenge eviction" phenomenon - it's my belief that of the (very few) revenge evictions that take place, most are by landlords who've reached the end of their tether with unreasonable, demanding tenants, and of course, it often seems that local authorities are happy to take their word, without checking with the landlord. Most tenancies are in fact ended by the tenants, with just 9% ended by the landlord.

Reply to the comment left by "Mandy Thomson" at "13/09/2014 - 11:32":

well tbh when I say eviction it never actually came to that - after much to-ing and fro-ing of letters and unpleasant visits accompanied by our then letting agent, during which she screamed and swore at me and spat remarks such as 'get out of my house' she eventually just left when we gave her 2 months notice to quit - (relatively easily I suppose if you disregard the mountain of bill letters which continued to arrive for months, complaints from neighbours about the noise and smell of the dogs and the utter devastation of our lovely little house caused during her tenancy).
She moved up just up the road (no references requested so possibly into council accommodation!) and her daughter and family were given a new build council house (so quite probably a successful conclusion to their long game anyway)

Reply to the comment left by "Denise D" at "13/09/2014 - 11:43":

Hi Denise

How awful! Some people... And yet, after behaving like that, they were given public housing, presumably with the rent paid by the state, and not having to even prove they were fit people to have the properties, as local authorities obviously have a duty of care to house anyone who needs it, so they don't check references - I personally believe that even within those parameters of housing need you should still have to prove your fitness as a tenant to some extent...

I've just recently lost my iphone, and was very lucky to get it back - we went to meet the man who found it, a very nice, pleasant chap. It turns out that he's homeless, although by no means dirty, dishevelled and certainly had his full faculties about him; in short, we wouldn't have known had he not told us. In his situation, I might have been tempted to keep the phone, either for my own use, or to sell it and raise some cash - he certainly wasn't obliged to give it back. However, he did and he was delighted with the £30 we gave him to say thanks - he would've got quite a bit more if he'd sold my phone. The reason I mention this is it often seems that people who have a sense of entitlement and rant and rave, and kick up a fuss (like your lovely former tenants), often seem to be the people who get all the help, yet those who quietly make the best of whatever little they've got, and are grateful for it, are often left to get on with it. Our society, and our welfare state, is often far from fair!

not to mention the fact that she was receiving housing benefit which she chose not to pay to us - and as far as I'm aware neither the council nor HMRC/Benefit Officers were in the slightest bit interested even tho' it seemed like a fraudulent claim to me