Moving in with partner- pay £400 rent? Is that ok?

I’d rethink the entire plan. Especially if his daughter is getting involved in these discussions.

Maintain a home where your daughter is unaffected by these other people.

Sounds like a recipe for disaster. Would you both be keen to do this - or even considering it in the first place - if the proposed scenario wasn’t financially advantageous for you both?

Who’ll be doing the housework?

It’s probably going to happen and I think £600 inclusive of bills for you and your daughter is fair.

What is his current mortgage payment? It sounds like three women will be paying £1k a month towards it plus bills and food. And dare I say, the bulk of the cooking and housework? Sounds like he's hit the jackpot!
With the right to evict whenever he feels like it and a house at the end of it. Make sure you are going into this with your eyes open.

In these situations you shouldn’t pay as much as a lodger, because you’re not one, you’re in a relationship.

I think:
half of all bills plus half of the interest part of the mortgage

paying off any of his mortgage isn’t right as you have zero rights to it.

interest on a mortgage is the same as rent

1/2 the bills as there’s 2 people in your family and 2 people in his
what his daughter pays is between them
£400 is cheap but if your all happy perhaps offer £500
security wise if it all goes tits up your out but tbh in a rented flat the LL could kick you out so your not really any worse off

I did pick up on you calling his daughter bratty I’d be concerned how that would pan out

Her daughter is still in college. She shouldn’t pay anything.

Totally agree. 100%

The more detail you give the less I'd be doing this.

Alarm bells here for me. Why on his income plus his daughters contribution would he be struggling without you moving in? Something isn't right. Even with his son moving out. And that just sounds like he only wants you to move in to cover his sons former contribution!!

OP, I think before moving in, I would NEED to know why he is struggling to pay the mortgage on the salary he's on, as to have been granted a mortgage in the first place, the lender must have been confident that he could afford to pay each month. Has he got a lot of debt that he's paying off - a big red flag for me! Is he a gambler? Does he have any expensive hobbies? Does he run an expensive car which he really can't afford? Does he do drugs? All of these could explain why he's struggling to pay the mortgage, and none of them are good. I know the cost of living is crazy right now, but his mortgage should be his top priority, so if he doesn't have a VERY good reason for saying he's struggling, I'd be most concerned if going into a live in relationship, that he's not good with money, and that for me would ensure that I stay put in my own place.

Don’t do it! Wait until both girls have moved out then get somewhere together. It sounds like he is poor at managing his money, his daughter is already resentful and you are giving up everything at the risk of you having no home if he decides to kick you out.

Don't do it. What a mess it is going to be. Why have you decided to do it?

My partner needs me to move in, as he needs extra money to cover his mortgage and expenses

You need to prioritise your own financial and housing security.

Your boyfriend needs to sort out a new house, he cannot be dependent on three women to subsidise his choice to have a house he can't afford.

Where do you live that you could find another rental with no problem?

Id consider carefully what would happen if he asked you to leave with no notice. Because he could. Will you have enough funds to cover emergency accommodation while you find a place? Will you have savings to cover bond? Are you absolutely sure that it will be easy to find another rental that you are happy with? Have you considered drawing up a lodgers agreement so you do have some rights? Who will be doing what around the house? Will you have extra commuting costs due to the move? What is happening to your furniture- will you need to pay to store it?

These are all just as important as what you contribute.

I would say 400 and that you will reassess after 6 months.

You always get the ‘don’t pay his mortgage’ screams but if you’ve no prospect of getting your own place then it’s just paying him instead of a landlord.
Sounds OK to me. £600 for both. Then half the bills and food each. You’ll both be better off. I’d think differently if you would struggle to match your current rental but as you’ve said you can easily get another at the same price I don’t see any issues.
Don’t buy any furniture or contribute to house repairs etc.
But it is a bit strange he can’t manage without contributions on his salary.

I think £600 plus half the food. I assume the daughter doesn’t pay rent plus bills. I’d also save so if it goes badly you hsve an exit fund or well you can “buy in” to the property.

@Susan7654 will you loose any universal credit by moving in? If so please take this into consideration as you may very well end up worse off.

i would not be moving in to much going on already.

His daughter is already sounding resentful and will seize on anything else she thinks is ‘unfair’.

My advice would be not to live in until both children have left home for good.

Don’t do it.

I wouldn't move in at the moment. You've been together 5 years and are only discussing moving in together because he needs the money.

If you decide to go ahead you need to discuss what's fair and reasonable. His mortgage payment should not be the basis of a fair calculation. You are paying rent not contributing to his mortgage. I would be concerned that with a net income of nearly £3400 plus £300 from his daughter he is struggling financially with a mortgage payment of £1400.