Your iPhone's keypad should automatically appear whenever you need to type text in an app. Although generally reliable, it sometimes doesn't pop up when it should. Or, it doesn't register typing as quickly as usual and, in some cases, freezes. If you're lucky, this is just a glitch that you can fix with a quick close-down and restart or a reset. If not, you may need to restore your iPhone or ask Apple for help.
Restart your IPhone
Sometimes, just turning your iPhone off and on again fixes glitches like keypad errors. Press the "Sleep/Wake" button on the top of your phone and hold it down until you see the power off slider on the screen. Swipe the slider to the right and wait for the phone to shut down. Wait a couple of seconds, and then press and hold the "Sleep/Wake" button again to start up the phone.
Reset Your IPhone
A reset closes down your iPhone and forces it to reboot its system. This may clear glitches or bugs that a restart doesn't fix. Press and hold down the "Sleep/Wake" and "Home" buttons at the same time. When you see the Apple logo appear, release the buttons. Your iPhone will shut down and then restart automatically, which may take a few minutes.
Restore Your IPhone
Restoring an iPhone takes it back to factory settings -- this wipes data off your phone, including apps, photos, contacts, songs and calendar entries. Before you start, run a backup in iTunes, so you can restore this data later. Connect your iPhone to your computer, open iTunes and select your phone from the list of devices. In the Backups area of the Summary tab, select "iCloud" or "This computer," depending on where you want to store the backup, and then "Back Up Now." When the backup is complete, select "Restore iPhone" and "Restore and Update." Once the process is done, restore your data by selecting "Restore Backup."
Get Help From Apple
If you can't fix your keypad problem, contact Apple Support. The company runs an online chat service or you can schedule a callback through its website. In both cases, you must provide your iPhone's serial number and sign in to your account before you can talk to a rep. To find your serial number, tap "Settings" and then "General." Select "About" and swipe up to find the number. You can also take your iPhone to an authorized Apple service provider or make an appointment at a Genius Bar. Keep in mind that Apple may charge if your iPhone is out of warranty.