Will AT&T still activate an iphone 4?

Like, if I buy a cheap iphone 4 will they activate it? Or does it have to be through their company?

AT&T is a GSM network which uses sim cards GSM PHONES ARE NOT ACTIVATES

Verizon Sprint as CDMA whose phones require activation

These are incompatible technologies:
A CDMA handset will never ever ever ever, work on the a GSM network and vice versa!

re IPhone 4

This THREE YEAR OLD iPHONE4 was discontinued by Apple 5 days ago when the IP5S & 5C were announced

On 12/09/2012 the iPhone5 was announced IP 3GS DROPPED,
like the year before IP4S IN, IP3G OUT… On 10/09/2013 no maths IP5S IN

Apple only support LAST 3 iPhones, discontinued means no longer sold by Apple, any future upgrades will in the main be for supported phones some new apps just WON'T WORK re IOS 7, will in the main be themes which the IP4 will get

The 5Mp camera IP4 may be the cheapest when compared to other iPhones but to invest any money in an OVERPRICED device is severe waste as in 2 years you will be using a 5 year old device that came out in 2010. Many have already upgraded from the IP4 in 2012…
http://www.itproportal.com/2012/09/06/8gb-iphone-4s-version-be-introduced-iphone-5-launch/
http://www.gsmarena.com/...ew-490.php

There are newer phones better phones and they cost a lot less*** giving you more than the 8Gb on the IP4, you should look at eg Sam Gal ACE II or the Lumia 620 for phone with a secondary camera for video call microSD expansion Wi-Fi, GPS, DUAL CORE… AND BLUETOOTH MEDIA TRANSFER (Sharing) which no iPhone even the IP5 has (photos / music Can't be shared if one phone is an iPhone
)
Here are the specs only if these phones are Gold Plated will it come in above the IP4 http://www.gsmarena.com/...hone2=5147

You can get a pre-owned IP4 for whatever price which has NO warranty

Or you buy NEW, which includes these features
BOXED braking the seal, Warranty and (100% free new phone smell) receipt and knowing say 3 months ago it was just components