It’s a good practice for each of your team members to have their own personal business phone numbers. There are many reasons why they shouldn’t use their personal cell phone number for business, so you’ll want to give them their own phone number through your VoIP provider or phone system.
You can change your voicemail password by calling (800)-331-0500 from your iPhone. You’ll reach AT&T’s automated customer service menu which will ask for your phone number and billing zip code. A few seconds later, the message “Password Incorrect – Enter Voicemail Password” will appear on the display of your iPhone. Enter the last seven digits of your cellphone number to change your voicemail password. I strongly recommend that you read AT&T’s support article on changing your voicemail password before attempting to do so.

My iPhone rings for 15 seconds – which is actually eight rings – before it goes to voicemail, but even that’s not long enough if I’ve put the phone down in another room or it’s zipped into a pocket in my jacket.
Voicemail is a method of storing voice messages electronically for later retrieval by intended recipients. Callers leave short messages that are stored on digital media (or, in some older systems, on analog recording tape). Originally, voicemail was developed for telephony as a means to prevent missed calls, and also to facilitate call screening.