Samsung SM-S975LZKATFN - Manual (Page 83)

Speed Dialing
Once you have stored phone numbers from your Contacts List, you
can set up to 99 speed dial entries (2-100) and then dial them easily
whenever you want, simply by touching the associated numeric key.
Note: Speed dial location #1 must be reserved for Voicemail use.
Setting Up Speed Dial Entries
Important! Speed dial location #1 is reserved for Voicemail. No other
number can be assigned to this slot.
1. From the Home screen, tap ➔ (Keypad tab).
2. Press and then tap Speed dial setting. The Speed dial
setting screen displays a virtual list of locations with the
numbers 2 through 100.
3. Tap an unassigned number slot. The Select contact screen
displays.
4. Tap a contact and select a number to assign it to the speed dial
location. The selected contact number/image is displayed in
the speed dial number box.
Call Functions and Contacts List 76