10% of income is fair ‘rent’

Why do people compare it with renting somewhere "in the real world"? You're family, he's not a lodger. Surely you don't charge the market rate?
Well, obviously some people do, but I do not think it's the same. Landlords are doing it for profit.

CTF? Lol.

In 16 years, my kids ones grew from £250 to....wait for it....drumroll.....£275.

Or he has to pay for a PA to provide that type of support and help him manage his PIP.

I do a similar thing with my son's PIP. That doesn't go towards the household pot at all. That goes firstly into his savings, so it is out of his account and can't be spent on Monsters and Lego and Minecraft. Then we identify what the PIP needs to be spent on. He has regular appointments in London, and taxi and peak rail travel can be £100 plus.

Did you plan on keeping them forever?

OP your son is absolutely right when he says it's unfair he pays you 10% rent

A fair amount would be 30%. That's probably not the suggestion he wants to hear, mind.

It doesn't. I've no idea why people do this.

I'm beginning to think the 'I could never CHARGE my child to live in their OWN HOME!' pearl-clutchers that always pop up on these threads are stealth-boasting just a tad. As in 'I can afford not to charge.' Either that or they haven't untied the apron strings yet.

You are assuming that all of us have children that will be able to successfully live on their own.

10% is very reasonable. I do approx 30% - so a third to the housekeeping pot, third to save and a third for him. But with the caveat that he is probably about paying his way now, so any pay rise etc will just be split between savings and his spending money.

He is autistic and probably ADHD (on a waiting list) but actually he is very happy to pay, he feels good about being an adult and contributing. Plus we always told him that we were happy to support his hobbies etc when he was younger and not earning, but he would be expected to contribute to food and electricity/gas costs once he was earning. So it didn't come as a surprise.

There is a spreadsheet on the fridge of ALL our outgoings, food, council tax, mortgage, water, electric, gas, phones, prescriptions, everything. It was a bit of eye watering to me when I did it, but he can clearly see what we pay out every month.

@Janiie if you put pip in a savings account who is going to pay for the extra costs incurred for his disability?

Can you agree with him to put some finances forward to an accountant type meeting, someone specialising in this sort of scenario.

agree the advice will be independent, you can be there and go over his finances etc together

perhaps if he hears from someone independent he will accept it. And you can have a follow up appointment to discuss wills or trusts or anything necessary

So your plan for him to learn the value of money is for OP to cover all of his expenses, and give him more money for savings, during a cost of living crisis. That's going to treat a working adult the value of money?

What is your dont understand that different people have different finances?

Sit down and show him how much it costs you to house him. The energy bills, minus the standard charge, a third. How much less a house would cost to rent with one less bedroom. A third of your grocery costs. He obviously pays you substantially less than he costs. Adults pay their way, he's not a child, so he pays his way.

PIP is for his expenses he has now. He has 90% of his income available to save to move out one day. He is just wasting this on takeaways as he isn't able to manage money yet.

Why is it so hard for you to understand that some people can't afford to add to it, or cover their adult children's expenses 🙄

Why didn't you add to it? You want to show him the value of money by taking his PIP and 10% of his parttime earnings but didn't think to teach him the value of money by having any savings for him? Yes granny did but what about you?

Better late than never but put his pip into a savings account along with this 10% you think he should give you so he can infact afford to move out one day.

No grabby at all. It's a life lesson which is part of parenting. They need to pay their way. Or they become the sort of partners who don't want to 'share' their money with their other half.
Plus some parents need it.

We charged ds1 10% of his take home pay initially, on the understanding he was saving for a mortgage. He’d finished Uni and took a training post. When his younger DB started an MA which we supported him through, we told him to stop paying.

Make it really clear.

“You have two options. 1- if you chose to live here then you contribute 10% of your earnings into the costs of running this house you chose to live in. 2- the other option is you find somewhere else to live and you fund it entirely yourself.”

Pip is not meant to be saved. It’s meant to cover the extra costs involved in helping a person with a disability to become more independent. So things like taxi fayres to appointments and similar things OP has mentioned.