Payment slip, receipt. Except that it wasn't any ordinary receipt, it was printed in four or five copies, on autocopy paper, with a long account number (starting with number of the local sdk unit of the recipient), extra parity checks on the related document number ("the call on number"), signature and stamp of the clerk who took the cash and booked it, or passed the money from one account to the other. To differ from today's banking, the money really changed accounts as soon as last Enter was pressed.
This served as a proof of payment - two copies to the payor (one for his own archive, one to present to the recipient), one for sdk itself and one for the recipient's bank. There were only two places where such a payment was accepted - the sdk and the post offices. Perhaps banks too, but I'm not sure if it could be any bank or it had to be payor's or recipient's bank.
Printing payroll meant perhaps hundreds of these slips, because the workers' loan payments went straight out of the payroll, and for each municipality where the workers lived there was a municipal tax of some sort, plus some parts of municipality would impose a voluntary, ahem, self-contribution (for one, left side of Čurda had one to build the sewers while the other didn't), and they all had to go to different accounts, and the whole payroll wouldn't pass muster at sdk if one of these had wrong amount.
Of course, we at stour once had a problem with a (character band) printer which had hammers for each character column. The character band was made of steel, and had character shapes embossed in it; this band would rotate above the ink ribbon and the paper would scroll beneath them. When the appropriate character would come against the position where it should be printed, the hammer would kick the paper and the ribbon against the band, and that would leave an impression on the paper.
The trouble was that second most significant digit was simply faulty and not printing, so it had the millions and the last coin correctly, it was just missing hundreds of thousands. Which passed muster of four people, who all checked the lower end of amounts. Where it was correct, actually. We noticed only when we printed the recap reports, where a missing column became obvious. So nothing, more paper to recycle. We ran that through the other printer, and this one got fixed later.