I think £480 is just the start given that is what you would lose in tax credits.
Food, hot water, toiletries and all those little extras that sort of become part of your weekly shop soon add up.
I would make a contract that what ever he pays per month, what ever childcare he does, has nothing to do with paying towards your flat. Otherwise shared ownership could end up being a 3 way split.
I think if your Dc get on with him and it is a ltr then I would agree to him moving in for a few months to see if you can live together and if you do then it would be with a view to selling and him at the very least matching your deposit with a view to selling your flat and buying a bigger place together.
Ultimately it doesn’t matter that you and your children get along with someone and you love that person and have been in a ltr with that person.
Whether you consider yourself single childless and poor or you have children, property, and an income everyone should ask themselves 2 questions.
They might seem mercenary and selfish but it will save you in the end from sometimes years of misery.
What is this other person bringing to the table.
and
Is this person going to make my life easier?
This isn’t about how much you love someone or how long your ltr is.
It is purely based on what help and what financial benefit this person will bring to your life.
Having extra childcare so you can go out and earn more money to make up for the losses he will incur is not a reason to move someone in even though the relationship’s next step is to live together.
At the very least this guy should be paying you £800 per month to just break even to where you are now
If he is only going to pay you £200 per month then at £10 per hour you would have to work an extra 14 hours per week to go somewhere to being in the same financial position you are in now and that isn’t taking off tax and NI so it would be more hours to cover those things.
Tread very very carefully.
If he is genuine and wants to be a team, moving you all as a family forward and has savings and income to make sure you don’t financially suffer then I would think moving in together is the way forward.
Working all hours to pay for a guy to be eating, drinking, sitting on your sofa watching tv and generally making a mess which you have to clear up when you get home under the guise of him doing childcare that you wouldn’t need if he wasn’t there is a sure fire way to an unhappy relationship and unhappy life.