Straight talk promo codes are pretty rare. So I am always a little surprised to see them when they appear.
Straight Talk is offering a 50 percent discount on selected phones ordered with airtime. (The image below is from an earlier promo code. )
If the link doesn't work for you, there are still some pretty good stand-alone discounts on various handsets.
The back to school sale includes:
There appeared to be a temporary glitch in the March 2018 code, but it turns out to have been canceled for "vendor legal reasons". I'm not sure what that means, but it may have something to do with the fact that the Straight Talk brand is a collaboration betweeen America Movil (Tracfone's parent company) and Walmart. So this cancellation of this code may be related to that relationship.
They have had a few promo codes before, so I hope this gets sorted out eventually.
The fine print appears to say that it doesn't apply to iPhone purchases. I haven't tested it on everything they offer, but it seemed to work on all the other smartphones I checked.
Update 8/4/2013: No longer valid.