Email, SMS, or WhatsApp: Picking the Channel That Actually Gets Read

A confirmation email costs you a fraction of a cent. An SMS to the same guest costs a few cents. Both carry the same sentence. The difference is that one of them gets read within minutes and the other might get read on Sunday, or never.

That gap is the whole decision. The question worth asking is which messages are worth paying to be certain about.

What the numbers roughly look like

Be careful with the figures floating around the industry. The famous "98% SMS open rate" gets quoted constantly and nobody can point to a current source for it. What is reasonably well established, and what your own sending will confirm within a month:

• Email open rates in hospitality land somewhere in the 20% to 40% range for a list that knows you. Anything above that usually means a small, well-scrubbed list. Delivery is close to free, so you can afford to be wrong.
• SMS gets read at dramatically higher rates than email, and fast. Most of the reading happens in the first few minutes. It costs real money per message, and pricing varies by country and carrier, so check your provider's rate card for the countries you actually send to.
• WhatsApp sits between the two on cost in most markets and near SMS on attention. It also allows a genuine conversation, which SMS technically does but nobody enjoys.
• Viber matters regionally. In Slovenia, Serbia, Greece, and a handful of other markets it has real penetration, and there it behaves much like WhatsApp does elsewhere.

Rather than trusting anyone's benchmark, send the same reminder over two channels for a month and count. Your list, your city, and your guest age profile will move these numbers more than any published average.

What each channel is actually good for

Email is for things with substance. A booking confirmation with directions and parking notes. A monthly newsletter about the new autumn menu. An event invitation with a ticket link. Anything the guest might want to find again later, because email is searchable and SMS is a scroll of noise.

Email is also where you put anything with length. Nobody reads a 400-word SMS, and if you split it into three parts you have paid three times to annoy someone.

SMS is for time-critical, short, and consequential. The 24-hour booking reminder. "Your table is ready" when someone is waiting at the bar. A same-day cancellation notice because the kitchen flooded. The defining test: if this message arrives four hours late, does it still work? If no, that is an SMS.

WhatsApp is for conversation and for markets where it is the default. In much of Europe, particularly the German-speaking countries, the Balkans, and southern Europe, WhatsApp is where people actually message. If your guests live in WhatsApp, a booking reminder there feels normal rather than intrusive. It also handles the follow-up naturally: the guest replies "can we move it to 8?" and you have a thread, not a mystery SMS from an unknown number.

Viber matters regionally. In Slovenia, Serbia, Greece, and a few other markets, Viber has real penetration. Worth checking what your guests use before assuming.

When SMS is worth the money

Work it backwards from the value of the thing you are protecting.

A booking reminder for a table of two at 40 EUR a head protects roughly 80 EUR of revenue. An SMS costing a few cents protects that. Even if the reminder only prevents a no-show one time in fifty, the arithmetic still works comfortably. That is why reminders are the clearest SMS use case in hospitality.

A marketing blast to 2,000 contacts announcing a new dessert is a different story. At a few cents each you have spent real money to interrupt people about a dessert. Email that.

The rough boundary: SMS for operational messages tied to a specific booking or a specific person waiting. Email for anything broadcast. WhatsApp can do both, but the template rules on business messaging mean marketing sends need pre-approved templates, which slows you down.

If you want to put actual numbers on this, our repeat guest revenue calculator shows what a returning guest is worth over a year, which is the number you should compare your messaging spend against.

The consent side, which is not optional

Under GDPR, and under the ePrivacy rules that govern electronic marketing across the EU, sending marketing messages to someone needs a lawful basis. In practice that means consent for most restaurant marketing, and consent has a specific shape.

Consent must be freely given, specific, informed, and unambiguous. A pre-ticked box is not consent. A checkbox buried in your terms is not consent. "By booking you agree to receive our newsletter" is not consent, because the guest cannot book without it.

Transactional is not marketing. A booking confirmation, a reminder for a table the guest reserved, and a notice that you are closed tomorrow are all part of delivering the service the guest asked for. You do not need marketing consent to send those. You do still need to have told the guest what you do with their data.

The soft opt-in exists but is narrow. Most EU member states allow marketing to existing customers about similar products or services, provided you collected the contact details in the course of a sale and gave a clear opt-out at that moment and in every message since. The exact scope varies by country, and some national regulators read it more strictly than others.

Separate consent per channel. Someone who agreed to emails has not agreed to SMS. Ask separately, record separately.

Opt-out has to be genuinely easy. An unsubscribe link in every marketing email. A STOP keyword that works for SMS. And when someone opts out, it has to take effect quickly and stick, including across any list you re-import later.

Keep the receipts. You need to be able to show when consent was given, what the guest was shown, and through which form. If your booking system does not store that, you are relying on memory in an argument you will not win.

Rules differ between member states in the details. Check your national data protection authority's guidance, or ask someone qualified, before you build a campaign on an assumption.

A sensible default setup

For most restaurants, this works:

1. Booking confirmation by email, immediately. Full details, directions, your cancellation policy, and a cancel link.
2. Reminder by SMS or WhatsApp, the evening before or the morning of. Short, with a one-tap cancel link. This is where the money is.
3. Marketing by email, with a real consent checkbox at booking or at the table. Monthly at most, unless you have something genuinely worth saying.
4. Replies into one inbox. Whatever the guest replies on, your team should see it in the same place, not scattered across a phone, a Meta business account, and an email alias nobody checks.

The short version

Pay for attention where attention changes the outcome. A reminder that saves a table pays for itself many times over, so send it on the channel your guest reads. A newsletter about the new dessert does not, so email it. Get consent per channel, in writing, with an opt-out that works, and keep the record. The restaurants that get this right send messages that arrive when they matter and are easy to answer, which usually means sending fewer of them than everyone else.