On the right side, there is a SPECIAL OFFERS. Click on See Details, you will see the pop-up for the discount details, close it out. Then click on Add to Cart and check out. You will see the 25% discount being applied.
For those of you with newer vehicles which include built-in LTE, OnStar is offering UNLIMITED in-vehicle WiFi for $15/ month. (No tax, in NJ at least). Savings of $10/month (Unlimited is normally $25.) OnStar uses AT&T, so speeds MAY slow after hitting 22GBs. This will be a grandfathered special: it will stay at $15 until you cancel. Must sign up by 10/31/19.
UPDATED to reflect AT&T's ongoing accessories discount, which can be found on this page:[att.com]
"Buy 3 Accessories, get 20% off. Available at select stores and at att.com. Pricing not valid with other discounts. Limit 10. Exclusions apply. Restocking fee: 10% on accessories over $200. Other restrictions apply. Subject to change without notice."
AT&T Wireless has BOGO offer: Buy one eligible iPhone and an iPhone XR on us when you buy both on AT&T Next Installment plan. Plus get $300 Gift Card when you order on line. See websites for additional terms and conditions. Shipping is free.