Sometimes the hosting company doesn't keep track of it either. I recently was involved in a datacenter decommission (20yo) and at the end of the day a shit ton of hardware was still happily humming along, nobody claimed it nor did anyone keep track of whose it was (most likely they once did but moved asset tracking platforms which missed certain things).
About a decade ago another company I worked for had a similar thing where we expanded the datacenter and started keeping accurate track of new assets. Again, bunches of devices were left over with no traces at all in asset or order tracking and entire racks of cable runs had to be cut out with chainsaws (after the power was removed). We had a notorious salesperson that would often allow 'good' clients in a pinch (often due to administrative and physical disaster at neighboring centers) to get colocation and even dedicated servers, rush built/installed after hours and installed with "we'll do the paperwork on Monday".