Uniden 6.0 dect phone interchangeable with different 6.0 uniden

SOURCE: How do I remove the Searching display from my Uniden 2080 DECT 6.o?

I also looked at your manual. If the handsets are registered to your old base, you need to deregister them from looking for the old base. Then you need to register them to the new base. Hope thsis helps!

SOURCE: cant register/install a new dect 6.0 uniden 2060 phone

I had a similar problem which I finally fixed. You did not say if any of your phones registered.
First try the following recommended by Uniden Support:
Your phone(s) should be fully charged before putting them on the main base.
Unplug the battery from the phone by removing the battery cover and removing the connector. Then, push the # and * key together and hold while you plug the battery back in (requires some dexterity). Continue to hold the two keys until you hear a confirmation tone. This will force the phone to reregister. Put the phone on the main base (if you are sure it has a fully charged battery) and see if it will reregister it to solve the problem.
That did not work for me. So, I followed the instructions to de-register the handset (even though it hadn't really registered). But, I also pretended like the Base was not available (because using the base in this step also failed).
1) Press and hold the hang up and # keys for at least 5 seconds.
2) Move the cursor to select Base Unavailable and then press Select.
3) Select the base you want to deregister from, press Select and then move the cursor to Yes and select.
This causes the phone to delete any of its base information.
At this point, again insure that your phone shows the battery is fully charged and if it is not, put it on the stand alone charger base (not the main base). With the battery fully charged, place it on the base and try registering again by placing it in the main base.
If neither of these approaches help, contact support at Uniden.com.
However, my problems were cleared when I cleared the handset with the second set of instructions.

SOURCE: I have a Uniden DECT 6.0 phone set. I damaged one

On the base, open the menu and select Register Handset. The display should say Handset Registering.
On the handset you want to register, press and hold # until the handset display says Handset Registering (about 2 seconds).
1.
2.
DSL filterTelephone cordTelephone wall jack
45
In about 30 seconds, the handset display should say Registration Complete. Press Talk/fl ash and make sure you get a dial tone.
If...
Try...
you don't hear a dial tone
the display says Registration Failed --
Making sure the handset is fully charged, then start over at step 1.