Mind your own business is what I really want to say

MayBeMaw I love your answer.
Shout ‘Hello? Hello?’ Down the line if that question comes up.
Problems with the line, stick with it and no one upset.

I tell you what IS rude! Asking someone about their personal finance arrangements!!! What an absolutely revolting man, if you excuse my displeasure? I would look at his fizzog-grin and say"wouldn't you love to know?!" Then ignore him! How very very rude of him! Don't let him bully you any more that's my advice! It's your business darling nobody else's

Best answer, works every time.

The ploy of “forgetting” relevant details works well.
Suggesting to your brother she’s inherited the gene to be careful with money might flatter and distract him.
Claiming to have no knowledge as someone else has been involved removes responsibility from you. Refer your brother to your husband as he alone has discussed the purchase of the house with your daughter.
Alternatively, massively exaggerate your contribution so it is clear to your brother it’s untrue and therefore no longer a subject to be discussed.

i disagree with some these approaches, not in a theoretical but a pragmatic way.
he has control of the OP's mother.
she can only communicate with mother through him.
maybe mother cannot operate a phone.
if he chooses, he can cut off OP from speaking to mother.
they are 300 miles away; she cannot just pop over to see her.
so, for her own reasons, i think it wise to keep on the right side of him.
avoid too much directness, which does sound rude.
be vague, yes, she's very fortunate. how's things in mother's house?
that's what i think anyway.
good luck Op.

Just say you are not privy to the ins and outs of your daughter’s finance, and would not be so rude as to ask her!

'What do you mean?' is a good one for awkward questions.

M0nica

Listen to any politician being interviewed, you will soon get the hang of it.

??? love it MOnica!

If he enquires ask him what he has been spending his money on, how did he afford the car, house, sweater etc that should shut him up or tell him the accountant you now have wants to go over mother's finances to make sure they are in order and that any pension etc she is due is in her bank. You probably will never see/hear from him again.

Just say, mind your own business. He likes or lumps it.p

If he isn’t part of your lives, then tell him to mind his own business or wind him up by saying”Wouldn’t you like to know?!”

What is a DD? I'm presuming it's a daughter but why the double D?
A DC?

It’s rude to discuss money but if he feels it’s his right to know / ask he should speak to the property owner!!

grandtanteJE65 It is the OP's daughter, not her brother's.

They obviously found ways and means and as it is their business I haven't asked would be my response.

"housewarming present" great idea Jess.

I can't see why this bothers you unless there's some sort of family competition over the moral highground by emphasising the richer and poorer theme - if it's simply at the level of him being a nosey git then tell him he can ask her if he's interested, not you. He surely won't know if it's bought or rented will he? Unless he does some significant detective work on Zoopla etc.... Personally, if confronted directly, I'd try and turn the conversation to the housewarming present he's obviously planning to send her as that's the only real reason he needs to know.

Danish Farmor15
I am Danish too

My daughter has a great response if I ask a question too far
“‘I think you’ll find its none of your business!” Said with humour but gets the point across !

Great reply Nonogran. I would say same!

He doesn't have to know if he asks just say she's moved. He wouldn't know if she has rented or not. As the other have said buy your Mum her own phone.

It is no ones business whoever they may be WHAT you do with your money.What you want? to say ?then say it
What can he do about it Start as you mean to go on. Once you
give in to his questions and comments it will never end.

It's probably being mean that has given him the lifestyle he loves so much!
As others have suggested, why not buy your mother her own phone ? There is a range of phones available that are just basic , without all the bells and whistles and with a larger screen, and keys and also compatible with hearing aids.
If by any chance he queries how DD can afford to buy her own place, beyond commenting that it is none of his business, you could always say that you were happy to help her out, you can't take the money with you, and you are happier seeing her enjoy your support now.

Why do you need to be polite. Surely it just encourages him. You don’t need to be rude, but just say what you’ve said here...” its none of your business, go away!”

I think what's it got to do with you? is entirely appropriate. I mean, what has it got to do with him? It's your DD (and I must say you sound like a lovely mother!)