Different cameras

We currently have a 1080p doorbell and we’re wondering can we use a 2K doorbell and the same circuit or do we have to buy just a whole new unit?

Thank you

Your question isn’t detailed enough to give you a good answer. You don’t say whether you have a wired or battery doorbell.

Are you asking about whether you can use the same Homebase? If so, the answer is yes.

If not, I don’t know what you are asking. There are multiple models of doorbell cams and they have different storage devices and some can be wired to existing doorbell wiring and chimes and some can’t.