If you're looking for actual Net10 promotional codes for purchases, you're now out of luck. They do have offers for things like free shipping and sometimes a $10 or $15 gift card.
I found these codes in an old email. I'm kicking myself that I didn't get these up for you while you could still use them, but maybe they'll work again sometime in the future.
Promo code NTWB75OFF was good for a $75 discount on phones prices at $199 or above. This code expired on 01/01/2015.
Promo code NTWB20OFF was good for a $20 discount off a SIM card plus airtime card purchase. This, too, expired at the beginning of 2015.
That's because the three promo codes they used to offer no longer work. Earlier, to apply the codes you had to go the site, enter your zip code, and then add your phone to the shopping cart.
Then enter your promo code and hit "Submit". Also, in the "old days", after the discount had been accepted, you could add the second promo code and hit submit. This would give you a total of $8 off! Here's a demo of how it used to work:
The airtime and phone bundles like the one you see above are still offered and are one way to save some money.
Below you can find the information on the earlier promo codes for reference. I'll leave them up in case Net10 re-activates them someday.
Here are the codes.
Get $5 off any Net10 phone using code 44477. This code seems to require a purchase of around $30. Works great on the LG 300 offer below, but not on the $20 LG 200.
There are no other codes which increase your minutes, etc., like there are with Tracfone. Luckily, Net10 airtime costs a low 10 cents or less per minute.
As I mentioned above, other ways to save are by looking for airtime bundles.
The LG 300G Cell Phone, Net10 750 minute card $25 combo is a good option for an inexpensive phone.
If you prefer a flip phone, get the Samsung T201G bundle is also available for $25.
You can see a full list of these Net10 offers here.
So for $25, you get a phone plus an additional 750 minutes airtime card. That works out to a free phone plus tons of minutes for the first month. Pretty good.
And that's it. These offers go in and out of stock so if you want it, get it today. The best way is to click the free shipping link and enter one of the Net10 promotional codes after you've added your items to your shopping cart.
While Net10 seems to have phased out promo codes for now, you can still find them for the related (sister) brands.
Tracfone always has a set of promo codes for its airtime cards and sometimes even for its phones.
Promo codes from Straight Talk are more rare, though they did recently have one for $5 off smart phones.