Ideas for RoomKeyPMS

At this stage, if we have an arrival whose booking just dropped into the system and required us to take payment immediately, we are unable to print out the guest folio (invoice) until that arrival is checked in to the system. If someone comes in early (sometimes the cash payer is not the guest who is staying) and pay cash and won't come back later to check in because the room was not available, they still need proof of payment,  we cannot print out one which is not ideal.  On the other hand, once payment is taken and I cannot print out an invoice and that same arrival will not check in until after I finish my shift then I do not have any invoice for my auditing. I believe this is essential to be able to print out an invoice once the payment is taken, especially for same day arrivals. I hope this makes sense.