Excel VBA: Update rec if it exists, add record if it doesn't

I have 2 wkshts (diff wkbk's), "CurrentTracking" and "MasterTracking". "MasterTracking" is a wksht that will continually be updated and added to for the duration of a project (months); updates and new records to come from "CurrentTracking". "CurrentTracking" is a download from a freight companies website (only goes back about 45 days) with the status of a tracking # current as of the day it's downloaded.

I need a macro that will update the current status of a record on the "MasterTracking" based on what's on the "CurrentTracking". However, if the record doesn't exist on "MasterTracking", a new record should be added to "MasterTracking". The update process will be run 3+ times a week.

The unique field in both wkshts is the tracking #. The number of records in the "CurrentTracking" varies from download to download, and as I mentioned the "MasterTracking" will be added onto throughout the project.

Thoughts on how to do this easily?

The idea you presented is exactly what I was already thinking. I just don't know how to write that out in a VBA macro. None the less, thank you for the post.