Google has introduced a referral program for Project Fi that offers new and existing customers $20 in credit when using the program.

The “Refer A Friend” option, found within the Account tab of the Fi app, provides users with a code which they can send to their contacts; any person who signs up for Project Fi with the code will bag themselves and the referrer $20 credit on their next bill.

To qualify, the newly registered user must be signed up to Project Fi for thirty days and can’t have signed up previously. Additionally, the new user must have paid for two months of the service, and the existing customer’s account must be in good standing.

The number of referrals is limited to 10 and they do not apply to additional sign ups via the recently introduced Project Fi family plan. Note that contacts using the program will have access to the others name, contact info, and account activation status, also.

The referral program is running from now until the end of January 11, 2017, so if you want to save yourself some bucks, get sending those referrals.