[KolenCh]

It would becomes a power event on the UPS.

Not only you should not plug it in a UPS (the initial surge when a laser printer is on would likely surpass the power limit of your UPS too), a laser printer and an UPS should not be under the same circuit breaker. I know because due to a limitation to where I lived before, I have to put both under the same circuit breaker. Every time I print something, it is a power event (where I can hear that the UPS temporarily switched to battery powered mode.)

[Loic]

My UPS has a plug for the printer. It does only surge protection. This is convenient to have the full IT equipment of the office protected with just one box.

[KolenCh]

Laser printer is known to cause a surge event too. Normally there's a limited amount of surge protection available and routine surge would gradually used up the pool.

However, surge protection may not be as important. I heard an argument that it is basically snake oil (because an actual surge would normally be much more powerful and beyond a typical capacity they have, and some causes fire.)

[masklinn]

Does your UPS have a plug for laser printers, or just for printers?

It might be assuming an inkjet, which have much lower power draws: an inkjet will draw maybe 50W. A laser printer are generally in the mid-hundreds at least and some models can get into the high hundreds to low kW, you need a pretty heavy UPS to handle that and still power other systems.

[Loic]

For laser printer, it is specified on the plug. It protects only against power surge coming from the utility provider. It does not provide power to the printer, this is just a protection if your house is hit by lightning.