Mr B paid some cash into our lil Sam's account today (bearing in mind he's a poor student and needs it the second he asks for it) but because he paid in a cheque on the same paying in slip, the cash doesn't clear til the following day. How the fook are we supposed to know that cash and cheques should be paid in separately if the cash is to clear the same day !
I think that it depends on the which bank the cheque is drawn on. You used to be able to pay cheques into third party branches, but there is some potential for fraud around items being returned unpaid which means that it is discontinued.
You can probably pay cheques into your LTSB account over the counters of the bank on which the original cheque is drawn, however, I think for Money Laundering Regulations, you must have a pre-printed credit slip to do so (so you will need a paying in book). However, I have tried a while ago and some cashiers are unhappy to accept it (even though they are happy for you to pay your gas bill over the counter which is a credit to another bank).
That is generally the case in terms of a "Mixed Credit" as the bank systems can't distinguish between the cash and cheque elements.
However I don't think that it applies if you were using a "House Cheque" ie if lil Sam has his account at the same branch/sometimes bank as Mr B then it should (in theory) clear straight away like cash and not be treated as a problematic mixed credit.
And don't even ask about Scottish cheques being paid into Northern Ireland banks with a Special Presentation as it all gets much too complicated!
Paid in Cash & Personal Cheque ("Mixed Credit") into sons account at our mutual branch of RBOS on a recent Friday, cash appeared as cleared on the following Wednesday!! They explained the only way one could get funds from my account to sons account on same day in same branch was by utilising "CHAPS" transfer system at a cost of £5 a blob, due to "money laundering" !! One of the reasons all of our RBOS accounts have recently closed.
As I understand it current British Banking "clearing" criteria have been branded as usuary in the international markets.