Autistic adult child wracking up huge mobile phone bills

Get him on a GiffGaff contract. Those contracts only allow you to spend a certain amount each month and then the phone simply won't call. Good luck!

Thanks all, some very very useful advice which we will consider. 

He won't be ready. But the point is to begin to include him into the family's Business as a matter of passing the torch. This shouldn't approached as a lesson to teach, but an opportunity for him to begin to walk with you on these things. Start small. Open discussion on savings and future plans even if they simply involve a new hob. Getting into the details of all the nuances between cost and function - help him understand how to save for something which lasts and when to spend on the cheap won't matter. Maybe even end the day each month with a whisky or something which suggests stepping up into a responsibility. 

It is somewhere in our nature to walk beside our elders and learn to navigate life. He may look back on these moments with fondness. 

im guessing it will be mobile data use...

i used to do this when i lived in my parents and my dad refused to allow me to have the internet. i used at first bt openzone which cost alot, then i used mobile wifi, which if your not on unlimited contract for data it will be insanely expensive as i could use 300 gb or more per month and what do they charge by data like £30 per 1 gb or something? lol ....your lad might be using mobile internet but the issue might be that its mobile data.... to fix that get a contract that has unlimited data instead if thats the case.

I agree with the above that financial education is the answer. 

The moneysavingexpert website has some useful resources on financial education. You can download a free textbook which is now used in schools, containing the kind of things we all should have been taught at school but weren't.

https://www.moneysavingexpert.com/family/financial-education/

You could use this to help teach about budgeting and monitoring actual spend against budget on a monthly basis. How much does he want and can afford to spend each month? I assume that answer isn't £700, so the reasons for the difference between actual spend and budgeted can be explored. It will probably help if you treat the mobile spend like any other expense and not make that the whole focus of the exercise.

The resources should also help him understand the consequences of late payments and debt and how that might cause future problems in life. How can he understand the consequences of spending if he has not been taught these things.

Thanks Martin. See my comments to other advice.

Thank you. In conjunction with 'Martin's' comments these are great suggestions. He currently pays 'board' and his mum then manages his remaining wage, drip-feeding him money as and when he asks for it. He doesn't have to think of all the other expenditure, I've food, utility bills etc. but this could be contributing to the issue. Not sure if he is yet mature enough (or ever will be) to manage his money but it's worth a go. Thanks. 

Does he pay you anything for food and towards bills, or a form of rent? If not, introducing this might give him some more grounded appreciation about money and what is needed to live day to day. I would do some research on rental in shared accommodation in your area and what monthly bills would be like, if he were living in a shared house. Then I would ask him to pay some proportion of this to you and your wife, half, a quarter or perhaps less.

Have you sat him down and worked out a monthly spending / income budget? It's probably time he begins to think about how much everyone earns vs how much everything costs. If his whole pay check is going to a phone it's not a wise use of money unless he doesn't have to worry about the future. 

He's still young and being autistic will mature slower. If you'd like him to be more financially serious, book a date with him that works with his schedule to begin to talk through finances and once a month, look through the budget and evaluate. Don't judge, just allow him to look at the math. I might also suggest to make it an enjoyable time. Tea, cake, sandwiches, nibbles. 

Thank you again for your comments. We've reflected and it's made us appreciate even more that he does has autism and can't help his impulsive actions and that the phone is incredibly important to him. However, as parents we have a responsibility to try and teach him the value of money as we cannot continue as we are. Our next step is to frame it such that we have his best interests at heart and putting the phone in his mum's name is us trying to protect him wasting his money and spending what is, up to now, thousands of pounds on 'rubbish'. Will see how we go. Anyway, thank you again, and I sincerely wish you the best. 

OK - that helps "frame" the problem that you seek help with.

I now read that your primary problem is one of WORRY about/for him;

a) what he spends money on.

b) that you can see that he is not always paying / paying on time (his phone bill).

c) that he may not understand the value of money.

d) that he is only able to earn his own money due to help from you and his mum.

Items a, b & c apply to me.....but I get by....and have done for many decades.  I'm just different ..... undoubtedly more proficient than most in many ways, yet hopelessly inadequate in many others.

Item d - naturally, I cannot pass comment on due to insufficient information.

And.......thank you for your thank you.  We do have visitors here who "bait" occasionally under the guise of asking for help - naturally - different perspectives abound in this place - be assured that any comment I pass is purely with a view to help or to simply proffer my own opinion (which is understandably different to the norm!) when invited to do so.

Thanks, appreciate the different perspective. There have been monthly bills as high as £700, and numerous letters sent advising late or non payment of the bill. Personally I don't see that allowing this to continue is responsible or in any way helping him to learn the value of money. Yes he earns his own money but he wouldn't be in employment if it were not for me and his mum, but that's another story.

Autistic people often prioritize and value things differently, but that doesn't mean there is something wrong, just that they are different.

He is earning his own money, and then spending that money on things/services he wants.... so I struggle to see the problem here.