The payments are made by the agent, presumably fairly automatically. I can't see them wanting to be difficult. Glad there is no inheritance tax for the spouse, even if not the house she lives in! That will keep her more secure at least.
the thing is, the agent will be able to see that the money was paid into that joint account
married couples will often have joint accounts and I'm sure there will be many things being paid in there - interest etc - and out of there - and these have to be adjusted when situations change.
if you're having a tough time then I know it's natural to get bogged down in paperwork - I do that and also I like to be ultra prepared - but please don't worry, if you get stuck on anything then MN will be able to help.
It might help you to get some kind of involvement - my parents are actually wondering about putting my name on a joint account in case it makes stuff easier when the time comes. I'm not saying it's essential, it's just something that occurred to us. My parents don't like to pay anything by direct debit and what i don't want is a situation with one or both of them ill (they are neither in good health) and them worrying about that too.
Personally I'd rather they just did some direct debits but they are suspicious of such things!!
I can't see any need for you to tell the bank now, it will probably save some stress if you don't.
Sorry to hear that your dad is so ill. The joint account will stay open for your mother to access. It would only be a problem if the rent was being paid into a sole account in your dad's name and he then passed away, then the account would be frozen until probate was granted (which can take months). Sole accounts are good protection for all couples to the surviving spouse having access to funds. If he has other funds in a sole named account he might wish to transfer the funds in that account into the joint account (if he is able to) if your mother might need more funds in the short term than in the joint account.
From a capital gains tax perspective it is better if the property is in your dad's sole name prior to his passing, which you say it is, rather than joint names, assuming that it has gone up in value since purchase. This is because your mother would then have a base cost of the market value of the property when she inherits it, rather than the original cost which will reduce any capital gain if she needs/wants to sell the property in the future. Worth checking that the deeds are definitely in your dad's sole name (if there is any doubt).
I hope this makes sense but please say if you have any questions.
Be careful when notifying the bank about the joint account. When I was doing similar for our Mam I even said to the bank "the one thing that you must not do is close the account". They said "yes, that's clear" and then went and closed the account. This created a nightmare and we had to get the Financial Ombudsman Service involved. Everything was eventually sorted but with a stupid amount of unnecessary stress.