AIBU to refuse a tenant's vulnerable guest staying in my HMO?

At best it sounds like she is on a visa waiver & has likely overstayed that. It can't do any harm to dob her in to Border Force as an illegal immigrant.

Is there any scope to move your paying tenant to another one of your properties? Clean break etc

Where are single people supposed to live if they can't afford a property to live in on their own?

Or even get a dummy one? As suggested the tenant could use it as an excuse to stop her entering, she needn’t know it’s not real / active.

The OP said she didn't have the correct visa to get housed by the council, not that she didn't have a visa.

OP, could you get a ring doorbell camera? That way the tenant could use it as another excuse as to why he can’t let her in, if she tried returning, telling her that you will know if she’s there and he will be evicted.

Is it an EU country? How long has he lived in the UK? How long has she lived in the UK?

There are various ways you can bring her to the attention of the relevant authorities.

https://www.imsallegations.homeoffice.gov.uk/start

It's not a popular topic on MN, SuffolkMan, but it's interesting that the community to which the tenant and this woman belong are said to be keen to encourage him to house her (to help her disappear?)

Hence why I said that the "I don't want her here" - and this after letting her in through multiple doors - is probably just something he feels he'd better trot out in order to keep his own accommodation

That’s not the OP’s responsibility. She does have a responsibility to her paying tenants.

I'm glad you've recognised that your tenant is in a difficult position OP, yes he made a mistake but we're all human. Hopefully like you say with your backing that letting her in would risk his tenancy he'll be able to stand up to those pressuring him.

It’s just not true. In this situation, the LL is not running an illegal hmo. I have a lot of expert knowledge on this area.
if this was me, I’d approach the council and explain the issue and issue formal warnings to the tenant and put in a complaint to the police.

I'm surprised that nobody is picking up on the fact that she has no right to stay in the UK. If she isn't claiming asylum & doesn't have the required visa why isn't Border Force removing her?

I don’t think the tenant is technically vulnerable. He is helpful to his own detriment

Unfortunately it's to your detriment too, @Poster555 - something I doubt he truly cares about despite the bleating, especially as it now turns out he's letting her through not one but three doors

Though "I don't want her here" may be trotted out for your benefit I'm afraid I wouldn't give it much credence, and while it's understandable that your main motive is to keep her away I still think a very hard line is needed here

So he seems to "fear people in authority"? Fine - then let yours appear to be the greater one, stick purely to what you have to do, and avoid any and all manipulation

Typo

Surely you don’t need a court order to evict her as she’s not your tenant? She’s essentially a trespasser there against the will of the landlord and so it seems all the legal occupiers of the house, including the one who let her in in the first place.

Sounds like formally threatening the actual tenant with eviction if he allows his friend back in the property is the way to go. You don’t actually have to evict him, but it means he can “blame you” if his other friends are pressuring him to take in this woman. And if he does continue then ultimately you should evict him. It’s not fair on the other tenants to have their home taken over by this woman causing trouble.

The police will just look for an easy fix. This is not it!

If you're in a city, they might have a NRPF social work team. If she doesn't have care needs or a child with her, they'd usually link her in with churches or offer support to help her move somewhere that she has a network (family or home country)
Hopefully it will help, but be aware if she's determined to stay here illegally then she might not disappear. But at least if the police know the score they won't be bringing her to the house. I do feel for your tenant it's a tough position to be in when you might feel a duty to help family but it sounds like he doesn't have the means himself.

They have no legal agreement to stay.

If they have said they are living at the property and misled that they have a tenancy agreement that's potentially fraud.

You don't have choices here.

Your tenant is in breach of their tenancy. You would be wise to bin them off.

You have a legal responsibility on the number of people living in the property for which you could be prosecuted.

Your insurance would be invalidated in these circumstances.

You have no idea what this person has done or whether they are cuckooing and carrying out illegal activity from the property.

The social welfare of your tenants is only your responsibility to a point. There are limitations as to how far you can go to look after someone before it turns into a situation where you are liable to be harmed if you do this.

You have other tenants in the property you have a legal and moral responsibility for too. As well as looking after your own interests.

You are a landlord not social services.

And as cold as that might sound, you could make a situation much worse if the council revokes your licence for an HMO and everyone is made homeless.

Realise that you can't save everyone and that there are limitations even for a good landlord.

From OPs updates, the unwanted tenant doesn't have the correct VISA and can't claim benefits.

There must come a point where someone thinks that as bad as their old life might have been, being homeless and penniless somewhere else isn't a viable solution.

As much as it might be a temptation to help with giving her temporary housing privately, her situation really won't change for the better.

I have told him that I will speak to any official bodies that are trying to pressure him, and to the ‘friends’

Apart from quite rightly covering yourself in case of comeback, I'm not sure why any "presssure" your tenant's under is your problem to fix, @Poster555?

You've not indicated that he's vulnerable himself, so given the lies he's already told ("it was a one off emergency") I'd be taking a very hard line about NOT allowing her in if/when she reappears, and suggesting he blames you if he really feels he needs an excuse

I'm also wondering if each tenant has their own lockable door and there's a lockable outside door to this HMO, because if so how is she getting in?

This sounds like good advice... the council etc have more resources to help her than you do.
It sounds like your tenant is in a difficult position and this would also help him