SMS vs Email for Review Requests: What Actually Works

When businesses start automating review requests, one of the first decisions they face is channel: should they send by SMS or email? Both have passionate advocates. Email is free, familiar, and trackable. SMS feels invasive to some business owners, requires a phone number, and costs more to send. But when you look at the data, the answer is not particularly close — and understanding why matters for how you structure your approach.

SMS open rates for transactional messages hover around 95%, and most are read within three minutes of delivery. Email open rates for the same type of message average somewhere between 20% and 35% on a good day. That means a review request sent via SMS is roughly three to four times more likely to be seen in the first place. More visibility translates directly to more action. In split tests run across thousands of review request campaigns, SMS consistently outperforms email by a factor of three to five in actual review completions.

That said, email is not useless. It works well as a follow-up channel for customers who did not respond to an SMS, and it is the better option for businesses whose customers have not provided mobile numbers. A two-touch sequence — SMS first, email follow-up 48 hours later — captures both groups. The SMS converts customers who are quick responders and mobile-first. The email catches people who prefer to act on things from a desktop or who need a second nudge.

The practical implication for local businesses is simple: if you have a customer's mobile number, SMS should be your primary channel for review requests. Build your data collection to capture phone numbers at the point of transaction. If you only have email addresses, use email — it still works, it is just a lower baseline. And regardless of the channel, the fundamentals remain the same: send promptly, keep it short, personalise lightly, and make the link direct.