It was always important to know how many workers were down a mine. A tally was kept by giving each miner two pit checks (also known as pit tallies). These were metal tags, often made of brass and stamped with an identification number. From 1947 onwards, the checks were also stamped "NCB," and this can be a useful clue when trying to date them.

When the miner went down the mine, he left one check with the banksman, and took the other check with him. At the end of his shift, the miner would return the check he had taken, which would then be matched up against the one the banksman had kept. In this manner the banksman would know when all of the miners were back safely on the surface.

Pit checks have now been replaced with magnetic swipe cards, making the metal checks obsolete (and therefore more desirable to collectors).