User Guide
Using iPhone with a Teletype (TTY) Machine
In some countries or regions, Teletype (TTY) machines are used by deaf or hearing-
impaired people to communicate by typing and reading text. You can use iPhone
with a TTY machine if you have the iPhone TTY Adapter cable, available for purchase
separately in many countries. Go to www.apple.com/store (may not be available in all
countries or regions) or check with your local Apple retailer.
Connect iPhone to a TTY machine: Choose Phone, then turn TTY on. Then connect
iPhone to your TTY machine using the iPhone TTY Adapter.
For information about using a TTY machine, see the documentation that came with
the machine.
For information about other accessibility features of iPhone, see Chapter 29,
“Accessibility,” on page 225.
Calling from Abroad
Set iPhone to add the correct prex when dialing from another country: In Settings,
tap Phone, then turn International Assist on. This lets you make calls to your home
country using the numbers in your contacts and favorites lists, without having to add a
prex or your country code. International Assist works for U.S. telephone numbers only.
For more information, see “Using iPhone Abroad” on page 72.
Changing Your Voicemail Password
A voicemail password helps prevent others from access your voicemail. You need to
enter the password only when you’re calling in to get your messages from another
phone. You won’t need to enter the password when using voicemail on iPhone.
Change your voicemail password: Choose Phone > Change Voicemail Password.
Locking Your SIM Card
You can lock your SIM card, so it can’t be used without a Personal Identication
Number (PIN). You must enter the PIN each time you turn iPhone o and turn it back
on again. Some carriers require a SIM PIN in order to use iPhone.
Important: If you enter the PIN incorrectly three times, you may need to enter a
Personal Unlocking Key (PUK) to enable your SIM card again. Refer to the SIM card
documentation or contact your carrier. Some cellular networks may not accept an
emergency call from iPhone if the SIM card is locked.
Turn the SIM PIN on or o:
1 Choose Phone > SIM PIN, then turn SIM PIN on or o.
2 Enter your PIN to conrm. Use the PIN assigned by your carrier, or your carrier’s
default PIN.
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Chapter 25 Settings