Referral credits are automatically applied toward account upgrades or renewals, or if you give the Gift of SmugMug.
If you outgrow your current account level and want to move up, we'll also apply your current subscription payments to the upgrade fee. You only pay (or have referral credits applied for) the prorated difference between the two.
To upgrade, visit your Account Settings and go to the Me tab > Subscription. Click Change Plan to select an upgraded plan type.
And don't forget to check out our features to see which account is best for you.