Godaddy has removed all promo codes for renewals in early April (which have been working for months to years) and seemed that impossible to save on renewals now, 1 code still works. It gives 20% for everything, and it worked for renewals to today (4/17/2014). The code is:
It doesn’t give great price ($12.17 instead of $15.17), however it’s better to use it and save few bucks than ignore.
However, numerous registrars offer better register/renewal prices right now. If you have at least 1 week before expiring, feel free to use these and save more:
Moniker.com (under $10)
Name.com $10.25 with promo code “NINJA” (my preferred registrar right now)
For bigger ones
If You own numerous domains (at least 9), it pays to get “discount domain club” membership and renew domains for good prices. Additionally, no need to hunt for promo codes each time when you need to renew – that means time savings!