I have a company phone that was recently updated. The prior owner of the phone is no longer with the company, but their apple id is still associated with the phone. How can I remove it?

If it is a "work" iPhone and your company is the owner, and if they have the original proof of purchase, your company bosses can ask Apple to remove the existing Apple ID using this link:--> https://al-support.apple.com/#/additional-support

Shouldn’t be this case, activation lock can be removed only by the previous owner, with the credentials that were used to activate that iPhone/iPad. Without those credentials, that device is useless to you (I mean that you can't change that Apple ID).

You can also take a look at this support article:--> How to removeActivation Lock- Apple Support

Regards

Giulio

Company phones should be managed and supervised so they can be restored by your IT department using the MDM solution they are using two manage the devices, without requiring the original Apple ID.

If you aren't managing iPhones, then you will need the Apple ID and password that was used on it, or to take it in to Apple as described with Proof of purchase so they can remove the Apple ID.