Q: Error message when texting

Try resettig your phone first. You wont lose anyting. Hold the home and off button down until the apple symbol comes up.

Then you need to do a restore from your backup in itunes. Connect to itunes, right click on your phones name on the left and click restore from backup, assuming you have backed up your phone recenty.

Check Settings>General>Internation>Region Format to make sure the correct region is selected.  Then go to Settings>Phone and make sure Dial Assist is set to On.

Just realized that if the reset doesnt fix it then this is a carrier issue and you should contact your carrier.

Those are the only settings that should effect the number formatting on your phone.  Sounds like your carrier may have done something unconventional to transfer your contacts from your old phone to your new one (such as using some proprietary software rather than iTunes).  The correct way to transfer your data to a new phone is to back up your old phone, then restore your new one to the backup of your old one, as described here: http://support.apple.com/kb/HT2109.  You may want to go back to your carrier's store and find out what they did.

Try setting the phone language to french and back to english, slide to tuen off the device, try again

I was having the same problem and here is how I fixed it.

I have fixed this problem on my iphone.

1. Delete all record of the problem number that will not except text messages.

Including contact, favorites, call log, text log...

2. send a text message to the phone number manually make sure to include the area code, no 1 needed.

3. click the sms button on your home screen, then select the number you just sent the message to and create a new contact from there.

Just fixed this by deleting the "+1 (1) (216) 116-11" entry in the Mesage list. 

Maybe someone from the mother ship will fix this bug!

Just encountered this problem today.  Have followed the suggestions of deleting the "+1 (1) (216) 116-11" entry in the message list, deleting the contact, (not in the favorites so nothing to delete there), call log, and text log.  Sent a text message to the phone number manually without the 1+.  Got the same error message.  Also tried setting language to French, and then back to English, and then turning off and on again.  Same result.  Region is United States and "dial assist" is on.  I haven't experienced this problem (yet) with any other telephone number.  Is this an Apple problem or carrier problem?

Forgot to add that this all occurred today when iCloud email was not working for several hours.

My wife had this problem for the past few days for a specific phone number. These instructions fixed it -- without having to restore from backup or contact the carrier.

http://www.timothydeblock.com/blog/2014/5/12/fix-message-sent-using-invalid-numb er-of-digits-msg-2114

1. Open Contacts -> select the contact -> select edit -> scroll all the way to the bottom and delete contact (delete multiple entries of the same phone number, my wife had five).
2. Open the Messages app -> select Edit -> select the red circle and then select delete. Do this for both the person and the messages you received.
3. Open the Settings app -> scroll down and select Messages -> turn off messages, by selecting the switch, and any other options turned on.
4. Turn off your phone and then turn it back on.
5. Go straight to messages and compose a new message and put in the phone number of the person you're trying to text. Send and that person should receive the text message. Add the person to your contacts and go back into message settings to turn on any other options you want on that you turned off.

John

only way I got around this was to start a new text message by typing in the number.  whatever the last number is change it to a letter that corresponds with the phone keypad.  the last number was a 4 for mine, so I placed a d there instead.  just use a letter in place for the number.  If its a 1 or 0, Im not sure what to do.  Also when they text back, you cant text back on the same message to them.  Its as if your texting each other on different texts.  That's a pain, but at least they are going though.  Hope this helps!             Allison