A couple of weeks ago "O" sent an e-mail to "G". Essentially it said: "Send us an invoice for £Megasum and we'll pay you by return. But please make sure the invoice reaches us before 31st March."
Needless-to-say "G" has yet to send the invoice. All it needs to say is: "Send us the money." We'll pass over why on earth "G" itself doesn't know how much to invoice "O".
Like all such entities "G" is short of cash.
Or is it?
It certainly spends lots of cash. From previous experience it's highly likely that when "G" gets round to sending the invoice and subsequently receives the cheque from "O", "G" will stick the cheque in a drawer for up to three or four months before they decide to deposit it in the bank.
This is not a one off. I know of several "Os" that have similar experiences with "G".