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What is your limitation for the number of facility codes per panel?


What is your limitation for the number of facility codes per panel?



There is not a limitation of facility codes per panel. There is only a limit of 16 card types. This is a Mercury limit but it DOES NOT translate to only tenants or anything like that. It is more like the number of bits. As you know there are a bunch of common bit length cards.


26 Bit

28 Bit

32 Bit

33 Bit

34 Bit

35 Bit

37 bit

40 bit


Think of each one of these as a card type. Any tenant that has a 26 bit card use the 26 bit card type. We combine the facility code with the card number to create a unique card number for that tenant and ensure this separates them from all other tenants of the same bits but a different facility code. So as long as the industry doesn’t create more than 16 different card types we will always be able to support all the various tenant card formats in one building and across all buildings.

For more detailed information please read Alternate Card Formats


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