This module will allow coupon codes to be used instead of affiliate URLs for granting referrals to your affiliates. This is handy for affiliates who advertise “offline,” where it is much easier to give someone a coupon code rather than a long URL string for your referral. The coupons will also grant the user a discount that can be defined by the administrator.

This is an old version, make sure to get the latest release from GitHub:

https://github.com/tripflex/whmcs-affcoupons