D series phone serial numbers?

We have a couple of systems and 150 or so D series phones, but one thing I can’t locate is the serial numbers for inventory purposes.

I see the phones all have their MAC address but there’s no indication if this is the serial number nor do I find the serial number in the phone software itself.

Can anyone shed some light? Searching something like “digium phone serial number location” gives telephony cards etc which isn’t so useful.

MAC is utilized as serial for these products.

Ah great! Thank you. I need to add them to our inventory system and needed to be sure.