The most straightforward way to is by looking at the physical hardware. Sony placed the serial number in two distinct locations depending on your model.
If your sticker has worn off or been removed, you can retrieve the serial number using a PC and a USB cable. check ps vita serial number
Is your PS Vita or running official Sony software ? The most straightforward way to is by looking
Registering your PS Vita's serial number with Sony can streamline the support process. check ps vita serial number