If you are sending review requests after every job or appointment and not getting the response rate you expected, the channel you are using may be the problem — not your message. SMS and email both work, but they work differently, and for most local service businesses the gap in performance is significant. This article walks through the data, the practical tradeoffs, the compliance requirements for each channel, and when it makes sense to use both.

The short answer: for local service businesses — plumbers, dentists, auto shops, med spas — SMS wins on volume and speed. Email wins on nuance and certain customer segments. The best programs use both.

The Numbers: SMS vs Email Performance

Before getting into strategy, here is what the research actually says:

Metric SMS Email
Open rate ~98% ~32%
Response rate ~45% ~6%
Avg. time to respond 90 seconds 90 minutes
CTR for review requests Higher 6% (2024, Birdeye data)

The 98% SMS open rate is cited widely, including by Infobip's SMS marketing statistics. The 90-second vs 90-minute response time comparison comes from Kenect, which analyzed business texting behavior across thousands of interactions. The 45% SMS response rate vs 6% email response rate is reported by Text Request.

These are averages across industries. For review requests specifically, the gap may be even more pronounced — a review request is an impulse action, and SMS catches customers in the moment they are most likely to act.

Why SMS Outperforms Email for Review Requests

Several factors explain why SMS gets more reviews:

1. The message is seen first

Most people check their phone within minutes of receiving a text. Email competes in an inbox that may have hundreds of unread messages. A review request that arrives via SMS while the customer is still in their car after their dental appointment is competing with nothing — it is the only thing on their screen.

2. The tap-to-review flow is shorter

A review request SMS with a direct link requires one tap to open, one tap to rate, and one action to submit. Email requires opening the email client, loading the email, clicking a link, waiting for the page to load, and then rating. Every extra step drops your conversion rate.

3. SMS reads as personal

A text message from a local business feels like a direct communication. An email from the same business is more likely to feel like marketing — because it usually sits alongside marketing emails.

4. No spam filters for short codes or verified numbers

Business SMS from a properly registered number (10DLC for US) arrives in the primary inbox. Email has aggressive spam filtering that can bury your review request before it is ever seen.

The Case for Email

Email is not the wrong choice in every scenario. Here is where it still makes sense:

Healthcare and HIPAA-adjacent verticals. Dental practices, chiropractic offices, and med spas often have patients who expect formal communication. More importantly, SMS for healthcare must avoid any PHI (protected health information) in the message body. An email subject line like "How was your visit?" with a review link, sent to a patient's email address, keeps PHI out of the SMS body entirely. If you are in a healthcare vertical, read our guide on TCPA compliance for SMS review requests — the rules for healthcare SMS are stricter than for general service businesses.

High-ticket B2B or professional services. A commercial HVAC contractor sending a $40,000 invoice is probably not going to win a review by texting the operations manager at 3pm. An email with context, a thank-you, and a review link embedded in the body is more appropriate for that relationship.

Customers who explicitly prefer email. If your service intake process captures email preference, use it. Never send SMS to someone who did not opt in.

Richer context when needed. Email allows you to include photos of the work, a summary of the service, and a link to your review profile. For complex services (HVAC installation, dental work, legal case), that context can improve review quality and increase the likelihood of a detailed, helpful review.

TCPA Compliance: What Changes by Channel

This is the section most blog posts skip. It matters.

For SMS

The Telephone Consumer Protection Act (TCPA) requires explicit opt-in before you send marketing or promotional text messages, including review requests. "Explicit opt-in" means the customer actively agreed to receive texts — a checkbox on a service agreement, a verbal confirmation documented in your CRM, or a digital intake form with a clear consent statement.

Key requirements:

  • Opt-in before first text. You cannot send a review request SMS to a number collected only for appointment reminders unless the opt-in specifically covers marketing/review messages.
  • Include STOP/HELP instructions in the first message of any new sequence. "Reply STOP to opt out, HELP for help."
  • Quiet hours: 9am–9pm local time. Sending a review request at 8pm on a Friday is fine. Sending at 11pm is a TCPA violation.
  • 10DLC registration. US businesses sending business SMS must register their brand and campaign with The Campaign Registry. Unregistered numbers face filtering and carrier fines.
  • No PHI in the body. If your business is in a healthcare-adjacent vertical, keep the message generic. "Thanks for your recent visit — we'd appreciate your feedback: [link]" not "Thanks for your root canal on Tuesday."

Our full breakdown of TCPA rules for SMS review requests covers registration, templates, and opt-in documentation in detail.

For Email

Email review requests fall under CAN-SPAM, which is less restrictive than TCPA. Key requirements:

  • Your business name and physical address must appear in the email.
  • Include an unsubscribe mechanism.
  • No deceptive subject lines.

CAN-SPAM does not require prior opt-in for transactional or relationship messages — and a review request sent after a completed service generally qualifies as a relationship message if it is not primarily promotional. However, if your email contains promotional content (discounts, offers), it becomes commercial email and the rules tighten.

Timing: When to Send Each Type

Timing affects both open rates and the quality of the review you receive. Research from Partoo and PowerReviews suggests:

SMS: Send within 1–4 hours after service completion while the experience is fresh. For same-day services (oil change, dental cleaning, plumbing repair), send the afternoon of the appointment or within the same business day. Avoid evenings after 8pm.

Email: Send within 24 hours. A one-night delay lets the customer settle, reflects on the experience, and is more likely to write a thoughtful review rather than a reflexive one.

Day of week: Wednesdays and Saturdays see higher review request conversion rates than Mondays. Avoid Fridays and Sunday evenings.

For more detail on timing windows by service type, see The Best Time to Ask for a Review.

SMS Review Request Template (TCPA-Compliant)

This template is for general service businesses (non-healthcare). Customize the bracketed fields:

Hi [First Name], thanks for choosing [Business Name] today. If you have a moment, we'd appreciate your honest feedback on Google: [SHORT LINK]. Reply STOP to opt out.

What makes this template compliant:

  • Uses the customer's first name (personalization, not PHI)
  • Asks for "honest feedback" — not a five-star review or a positive review
  • Sends to every customer equally — no sentiment screening
  • Includes STOP instruction
  • No incentive language ("discount," "free," "win," "prize")

For a full library of templates — including healthcare-safe variants — see Google Review Request Templates.

A/B Testing Your Channel Mix

If you are running a volume high enough to test (50+ transactions per month), consider running a 30-day split:

  1. Send SMS review requests to the first half of each week's customers.
  2. Send email review requests to the second half.
  3. Track reviews received, link click-through rate, and time-to-review.
  4. In week 5, shift 80% of volume to the winning channel and keep 20% in the other.

Most local service businesses that run this test find SMS generates 3–5x more reviews in the same period. But the result varies by vertical and customer demographics — test your own audience rather than assuming.

When to Use Both

A two-touch approach — SMS first, email follow-up — works well for businesses where a significant portion of customers are older and check email more than texts, or where the service is complex enough that the customer needs to reflect before reviewing. The sequence:

  1. Day 0 (same day as service): SMS with direct review link.
  2. Day 3 (no response): Email with a brief note and the same review link.
  3. Stop. Do not send a third request. Two touches is the ceiling for most customers before it becomes annoying.

Research suggests that 68% of customers who will leave a review do so after the first request. Another 28% respond to a follow-up. A third request adds almost nothing and risks opt-outs.

Practical Checklist: Getting Review Requests Right

  • Confirm opt-in for every customer before sending SMS
  • Register your number for 10DLC (required for US business SMS)
  • Include STOP/HELP instructions in the first SMS of any sequence
  • Send within quiet hours (9am–9pm local)
  • No PHI in the SMS body for healthcare verticals
  • Send to all customers equally — no sentiment filtering
  • Use a direct review link (not your GBP home page)
  • Send within 4 hours of service for SMS, within 24 hours for email
  • Test channel split if you have 50+ jobs/month

Sources

GBP Autopilot automates TCPA-compliant SMS review requests via Twilio — opt-in capture, quiet hours enforcement, STOP/HELP handling, and 10DLC registration built in. Plans from $29/mo, month-to-month. Start free.