Ask when the job is finished
The end of the job is the strongest moment to ask, because the customer is looking at the finished work and the result is fresh. Ask in person before you leave, then follow up the same day with a text that includes your link, so they have something to forward.
Ask when the customer pays
Payment is a natural second moment, because the customer is already thinking about the job and the relationship. Put your referral link and reward on the invoice or receipt, and add one line to the payment message. It costs nothing and it reaches every paying customer.
Ask after a good review
When a customer leaves a good review, they have just said in public that they would recommend you. Thank them personally and, in the same message, give them your referral link. Keep the thank you first and the ask short, so it reads as gratitude rather than a sales follow-up.
Ask at seasonal maintenance
A seasonal check-in gives you a reason to contact past customers that is useful to them, and their neighbours are often thinking about the same work at the same time. Offer help first, then mention your referral link. This is how customers from past seasons stay in touch.
Ask after a problem you fixed well
A problem handled well can leave a customer more loyal than a job that went smoothly. Once the fix is confirmed and the customer is happy, it is fair to ask. Wait until the issue is fully resolved; asking while it is still open will feel tone deaf.
Why asking every time beats asking once
One ask is easy to forget. Customers mean to pass your name on and then the moment passes. Asking at each natural moment gives them several chances to act when it is convenient, and makes referrals part of how you finish every job rather than an occasional favour.
What to say at each moment
The wording changes with the moment, but the shape stays the same: a thank you or check-in, a plain ask, your link and the reward. Use the lines below as starting points, then copy full versions from the referral text templates guide.