Which UK bank shall I join with for a current account?

You might want to clarify your question. At present, it makes little sense. Any bank that you join, and open a deposit account, by placing funds into the account, will create a 'current account' at that bank.

Your account stays 'current' as long as there are positive funds in the account. If you spend money from the account, using a paper cheque or debit card, as long as you maintain a positive balance, the account remains 'current'.

If you open a credit card, you must pay at least the requested portion of what you have borrowed, buy the date indicated on the monthly statement, doing this will cause your account to remain 'current' or in good standing. If you are late, it will fall out of good standing, and be considered 'late'.

The main thing you're looking for is good customer service. You'll want to put money in and take it out frequently, and you want the bank to reliably do all that and not mess it up. You also want there to be a convenient branch you can easily get to. Yes, we can do so much online these days but the one thing you can't do without actually visiting the bank is pay cash in. You never know when you might need to do that. So what banks are in your local high street or nearest town? Choose from those.

Thinking about all that, the "big four" of Barclays, HSBC, Lloyds and NatWest are all equally good. I've had dealings with all of them through being treasurer of various things, and I can't choose between them. My current account is with Lloyds and after 33 years, I have no complaints.

One to avoid is Santander. Their 123 current account pays a good rate of interest if you have money going in regularly (such as being paid by deposit into that account) and as far as my Mum is concerned, she gets her pension paid into it and getting that much interest is worth paying the fee of £5 a month. But their customer service is terrible and they've caused her a lot of embarrassment when they didn't set up a direct debit on time, and ignored when she told them she'd moved house. Anything beyond putting money in and taking it out seems to be too complicated for them. Mum is retired and has the time to argue with them, but I think you'd rather do without that hassle!