Short answer: Yes, but with care. Asking past customers for a Google review is one of the fastest ways to grow your review count — as long as (1) they actually gave you permission to contact them, (2) the ask is honest and consistent for everyone, and (3) you use a channel and tone that won't get you blocked or reported.
The riskiest thing you can do is dump a five-year-old spreadsheet of numbers into an SMS tool and hit send. Even if every one of those people was a real customer, you can trigger opt-out complaints, carrier filtering, and — if the phrasing tips into "please leave a 5-star review" — a policy violation with Google.
Last reviewed: 2026.
When it's fine to reach out to past customers
You're on solid ground when:
- The customer gave you their number or email as part of a real transaction.
- They didn't opt out later.
- The message is a one-time, low-pressure ask, not a marketing blast.
- You'd send the same message to a customer who might rate you 3 stars as you would to one who might rate you 5.
When it's risky
- You're texting numbers from a bought list, an old CRM you don't own, or a shared spreadsheet where consent is unclear.
- The last contact was so long ago the customer probably won't remember you.
- You're only reaching out to customers you think liked you (that's review gating).
- The message hints at, or offers, anything in exchange for a review.
Choose the right channel
Not every channel is equally safe for a cold-ish outreach.
Lowest friction. If the customer opted in at any point and you follow CAN-SPAM (real sender, physical address, one-click unsubscribe), a review request is fine.
SMS
Higher signal, higher risk. US carriers require your traffic to be registered under A2P 10DLC. If it isn't, most of your messages will silently disappear. Older contacts are also more likely to reply STOP or mark you as spam, which hurts your sender reputation.
Phone call
Slow but unambiguous. Best for high-value customers or when your list is small.
In person / at pickup
The highest-converting channel of all — and the least legally complicated.
Segment your list before you send anything
Before you touch a bulk-send tool, split your past customer list into buckets:
- Last 30–90 days. Send first. Best memory, best conversion, safest.
- 90 days to 12 months. Send in a second wave. Personalize with the job type or service.
- 12+ months. Only reach out via a channel they explicitly opted into (usually email). Skip anyone you have no clear consent for.
Also remove:
- Anyone who's already left a review.
- Anyone who previously opted out.
- Anyone flagged as a difficult account or unresolved complaint (fix the relationship first, then ask).
What to say
Keep it human. You're following up with someone who worked with you, not running a marketing campaign.
SMS template (recent customer)
Hi [First Name], it's Alex at Bright Smile Dental. It's been a couple weeks since your visit — if you had a good experience, we'd really appreciate a quick Google review: [link]. Reply STOP to opt out.
SMS template (older customer, safer wording)
Hi [First Name], this is Alex at Bright Smile Dental. We're catching up with past patients — if you'd be willing to share your honest experience on Google, here's the link: [link]. No pressure at all. Reply STOP to opt out.
Email template (older customer)
Subject: A quick favor from Bright Smile Dental
Hi [First Name],
This is Alex at Bright Smile Dental. Reviews on Google make a real difference for a small practice like ours — if you have a minute, we'd love your honest feedback here: [link].
Whether it's five stars or feedback we can act on, we appreciate you.
Thanks, Alex
Notice both templates ask for an honest review, not a good one. That's the difference between a request and a policy violation.
Common mistakes
- Blasting the same message to everyone. Personalize at least the first name and, if possible, the service.
- Sending during evenings, weekends, or holidays. Filters treat this as spammy.
- Only asking customers you think liked you. Google explicitly forbids review gating.
- Offering a discount, entry into a drawing, or a freebie. This violates Google's policy and, for some industries, professional codes of conduct.
- Skipping the unsubscribe/STOP language. Not optional.
Legal quick recap
- US SMS: Get consent, register for A2P 10DLC, honor STOP, follow the FCC's reasonable-hours window of 8 am–9 pm local time.
- US email: Follow CAN-SPAM. Real sender name, physical address, working unsubscribe.
- Canada: CASL requires express or implied consent and a clear unsubscribe.
- Google: No incentives, no gating, no fake reviews.
FAQ
How far back can I reasonably reach out?
There's no legal cutoff, but most businesses see steep opt-out rates beyond 12 months for SMS. Email is more forgiving.
Can I ask a customer to update or remove a bad review?
You can respond publicly, and — if they gave you contact info — reach out once, politely, without incentives. Do not badger them and never pay them to change it.
Can I offer a discount on their next visit for leaving a review?
No. Incentivized reviews violate Google's policy whether the review is positive or not. You can thank customers who leave feedback, but only after the fact and without linking the thank-you to the review itself.
How SoTrustworthy helps
SoTrustworthy tracks who's already been asked, honors opt-outs across every campaign automatically, and lets you re-engage past customers in staged waves so you don't torch your sender reputation with a single blast. That means you can safely reactivate an old customer list without spending an afternoon reading FCC rules.
Read next:
Ask every customer for a review—without review gating.
SoTrustworthy sends a compliant, perfectly-timed review request to every customer after the job — no filtering, no gating, just more honest 5-star reviews on Google.
