Just to be clear from above, and to answer your Post Title
Change NFC tag ID with NFC Tools
Unfortunately, you can’t change the UID on your NExT ( HF - Chip )
So as I said above, there is still a chance your work system with work with the NExT ( HF - Chip )
It has some similarities, with the DESFire implants -13.56MHz ISO14443A also has a 7 byte UID.
But it will ultimately come down to what your security system is “looking” for.
This is what I would recommend as your next step
You will have to do some sleuthing, to find out some more info about your work security system and get chummy with the security admins.
What I would suggest is thusly:- ( 2 approaches )
Easiest
Scan your NExT with TagInfo or NFC Tools and find out the UID, give this UID to the admin or
Go to the security office, Swipe your NExT on the enrollment system how they normally enroll a new card /fob, attach this info to your profile
Slightly more effort:
Scan your NExT with TagInfo or NFC Tools and find out the UID ( For your records )
At work, Scan your NExT on a reader ( You will be denied, but hopefully you get some feedback ( Lights, beeps, whistles, sirens )
then immediately following the shameful denial, swipe your actual work card.
Record the date and time along with the location of scan, This info will now be in the security logs.
Use this info to enroll your NExT on your profile
Links, as promised
https://dangerousthings.com/product/flexdf/