iPhone Voicemail is not open for users, so we never access directly or manage from different devices. Just like copy or move voice mail to another iOS device, restore old voicemails to new iPhone. Else you might need voicemail password after restore or change carrier/ number. In that apple don’t have any policy or service that recover voicemail password for you, because it’s carrier dependent. So, the only owner can access all voicemails through a password. After longer time to go, you might forgot voicemail password; Then recovery is so easy from carriers (Verizon Wireless, AT&T, Sprint, T-Mobile).
So, you can do through active information about how to do it from your carrier provider. Apart from USA’s carriers refer country wise carrier support page.
Steps for recover forgot voicemail password on iPhone: Wireless devices
Change/ Reset voicemail password from Verizon Wireless
Follow the same steps on Basic, Premium and Visual voicemail.
Press *611 and Type: SEND. Recovery information will be delivered to your number from carrier.
Through the Tall free call, (800)922-0204, Press 4 during customer audio menu, Go with “Reset voicemail password”. Might be required verification details. Follow the prompt for reset voicemail password.
Through My Verizon App: My Verizon App is #1 best way to recover forgotten voicemail passcode, under the Profile Tab you can change passcode with valid Verizon login details.
Reset voicemail password from AT&T
Call 611 or 800-331-0500 from your iPhone, enter your number starting with area code, then press 3 two times. Follow the instruction and Enter last seven digits wireless phone number.
Reset From AT&T website: Go to AT&T voicemail password change page, Enter User ID and Password. Next Profile > Passwords > Wireless Voicemail Password.
Save new voicemail password.
Update voicemail password on Sprint
In alternate ways, using My Sprint web or through the phone.
Dial *2 and Select account information or changes. Follow the onscreen instruction and reset voicemail passcode.
Sprint web account, My Account > My Preferences > Want to > Manage Voicemail Passcode. Then reset.
Reset Voicemail from T-Mobile
Here is the self-service code for reset voicemail password or Turn on/ Off password through shortcodes, #PWD# (#793#) and #PWO# (#796#) respectively.
Don’t be panic; you don’t need to take action for bypass way on reset/ Forgot voicemail password from iPhone running on iOS 10 (iPhone 7/ iPhone 7 Plus and more)/ iOS 9/ iOS 8 or later.