My company is modifying their corporate structure and I am going to be reclassified as an employee of a subsidiary organization. The work I do is already for the subsidiary and nothing will change in terms of my duties, title, or pay. Do I need to update my resume to reflect this change and if so, what would be the best way to communicate the change without using up too much space? I was just given a promotion a little over a month ago (mostly just a title change to more aptly characterize the job I was already doing) and I'd prefer not to use three lines of my resume to describe what is essentially the same job.
If it is only internal change, it is not that important but if your pay is now coming from a different payroll system, then I think it is a good idea to reflect it.
You can keep the description common but just add one more line to reflect the change in company
2019-Present: Current Designation, Subsidiary Company
200X-2019: Past Designation, Original Company
Tasks performed - 1
Task Performed -2
In tasks performed you can can explicitly again mention subsidiary company if you think it will help others to know your previous work was also for the same company.
Simplify. Your resume only has a few seconds to not get overlooked. Miring it down in trying to explain the genealogy of your workplace will distract the reader and get you tossed out before they ever get to what YOU DO.
You now have a small advantage. Pick whichever company looks better based on what story your resume is telling about you. Name recognition and industry reputation are a couple considerations that come to mind. Whatever the criteria, use that one.
If the minutia of which branch you worked for matters, that nuance can be discussed in the interview. Waste too much space on the resume and you'll never get to have that interview in the first place.