AT&T 1070 11 shows before every phone number (+1 twice)

Are these number that are in your directory? Have you reviewed the directory to see if they contain a one? When you review the CID are there two ones? In reviewing the redial it states you need to set the area codes for your area, says it's on page 42, but I find no instructions to do this, you may have to run through your menu to see if you can find it. It does state if the area code isn't set it will place a 1 in front of it. So if the CID come in with a 1 and it's not in one of the area codes you've set it's going to add another 1. There is a number in the front of the manual for support if you can't figure it out. I'm betting there's a way to tell the phone system not to add that one, but can't find it in the manual. Page 50 of the manual tells you how the area codes work and where to set them, but when you go to the page as instructed to set them, it doesn't tell you how. So basically, the manual is messed up. OK, page 55 tells you how to alter the CID information. That's the best I can find. You can find the manual here

No, they're not in the directory. I tried setting the area codes for... maybe I should set up 1212 rather than 212 if I can. I'll cehck page 55! Thanks!

No go... caller ID also shows numbers like 112125551212

Could the issue be with the CID being provided by your telephony provider?

It won't let you alter it so you can then hit the redial with the correct information? @JefferMC I check my incoming CID and they all have the one and area code added, as I've never set the area code, but I'm on this wireless home phone which is cellular service so it probably ignores the one anyway. As far as it could be what the provider is giving, yes if the provider is giving the one than the phone system adds a 1 to the area codes not listed that would give you the double one. Only problem is the manual addresses it, but the instructions as to how to do it aren't there. So it will take some experimenting through the menu on the OP's part. 

No, it won't let me alter it to redial, oddly enough. I did set hte area codes, it does nothing.  I've been through the menus... maybe one day I'll go down to two lines and get another phone... 

Oh, and fwiw, I did set the area codes successfully but they only three digits! A four digit area code isn't programmable.

Jeffer... maybe but my other phones don't add a 1 automatically so it works. 

OK after re-reading the OP's issue he isn't using redial, where you repeat the last number you dialed. He's dialing the number displayed on the CID to return a call. My bad. So, the steps on page 55 to alter the number sequence before calling out is the steps they want. Still there should be a way to set up the local area codes to make it work. Since the phone system is adding a 1 Maybe setting up the local calling area would work. Without the manual giving specific instructions than like I stated it's going to take some experimenting. Or call the support number in the front of the manual

"Jeffer... maybe but my other phones don't add a 1 automatically so it works."

Time to stare and compare as to what's different in the programming of the phones.

The others are a Uniden and a Panasonic...