Panasonic KX-TGM420 Operating Instructions Manual page 86

To edit the number: [
•
Press [EDIT] repeatedly until the phone number
is shown in the 10-digit format.  [SAVE] 
[ ]: "Call block"  [SELECT]  Go to step 4.
3 [ ]: "Save call block"  [SELECT]
4 [ ] "Yes"  [SELECT]
5
Edit the phone number if necessary (24 digits
max.).  [SAVE]  [OFF]
Adding call blocked numbers manually
1 [MENU] [#] [2] [1] [7]
2 [ ]: "Block a single number"  [SELECT]
3 [MENU]  [
4 Enter the phone number (24 digits max.) 
[SAVE]  [OFF]
86 | P a g e
]: "Edit"  [SELECT]
]: "Add"  [SELECT]