WhatsApp vs SMS for restaurant marketing: cost and reach compared
Decide whether WhatsApp or SMS should carry your restaurant offers and booking messages by comparing reach, billing units, consent rules and template approval. You can price one real send on each channel, test both on revenue per send and set a default channel with a fallback.
For most UK restaurants, SMS wins on reach and WhatsApp wins on richness and measurement. SMS reaches any mobile number and is billed per segment of up to 160 characters. WhatsApp reaches only diners with an account, charges per delivered template at Meta's country rate, reports read status and needs pre-approved templates. Both need opt-in consent under UK GDPR and PECR.
Should your restaurant use WhatsApp or SMS?
Choose by audience and message type, not by which channel feels newer. SMS is the stronger default when most diners carry UK mobile numbers and your offers are short and time-boxed. WhatsApp fits when a message needs a dish photo, a booking button or a reply. It also suits venues where guests already message you on WhatsApp.
Many restaurant groups run both channels, with separate consent for each. Use the table below as a starting point, then test it against your own revenue per send.
| Your situation | Start with | Why |
|---|---|---|
| Mostly UK mobile numbers, short weekly offers | SMS | Reaches any handset, with no template approval step |
| Guests already message you on WhatsApp to book | Replies inside the 24-hour service window are free under Meta's pricing | |
| The offer sells on a photo or needs a "Book now" button | Templates support image headers and link buttons | |
| Last-minute message, such as "tables free tonight" | SMS | No Meta review, so it can go out in minutes |
| Long messages, such as a new menu with prices | One charge covers up to 1,024 characters | |
| Small list run by the owner, no marketing team | SMS | No Meta business account, display name review or template admin |
| Diners who gave a number while booking, with no explicit opt-in | SMS, under the soft opt-in | PECR allows it with conditions; WhatsApp policy still needs explicit opt-in |
Both channels have one thing in common. Neither works without a list of diners who have agreed to hear from you. Mailchimp, Klaviyo and HubSpot send to a list you already hold. Purple Engage builds that list from Guest WiFi logins, as consented, first-party data.
Where do WhatsApp and SMS differ for restaurants?
The table compares the two channels on the axes that change cost, reach and risk for a restaurant marketer.
| Factor | WhatsApp Business Platform | SMS |
|---|---|---|
| Who can receive it | Diners whose number is registered to a WhatsApp account | Any mobile number that accepts texts |
| Billing unit | Per delivered template message (since 1 July 2025) | Per message segment sent |
| Who sets the rate | Meta, by recipient country code and template category, plus any provider fee | Your SMS provider, by destination |
| Length covered by one charge | Up to 1,024 characters in the template body | 160 characters (GSM-7) or 70 with an emoji or other Unicode character |
| Rich content | Image, video or document header, plus quick-reply and link buttons | Plain text and a link |
| What you can measure | Sent, delivered and read statuses | Delivery receipts only |
| Pre-approval | Meta approves every template before first use | None for message content |
| Free outbound messages | Service replies in the 24-hour window; utility templates in an open window | None |
| Consent for marketing | Opt-in under UK GDPR and PECR, plus Meta's WhatsApp Business Messaging Policy | Opt-in under UK GDPR and PECR, or the PECR soft opt-in |
| Sender identity | Business display name, reviewed by Meta | Alphanumeric sender ID of up to 11 characters, or a phone number |
Reach: every phone versus every WhatsApp account
SMS reaches any handset with a mobile number, including basic phones and phones without data. The diner needs no app, account or data connection. WhatsApp only reaches numbers registered to a WhatsApp account. Meta reports that more than 2 billion people use WhatsApp, but you cannot see which of your numbers are registered until you send.
Under Meta's per-message pricing, you pay only when a template is delivered. A template sent to a number without WhatsApp fails and costs nothing. SMS contracts differ on whether undelivered texts are billed, so check yours before comparing.
That gap shapes your list strategy. A WhatsApp-first send with SMS fallback for undelivered numbers covers both groups. It only works if each diner consented to both channels.
Read rates: what each channel lets you measure
You will see high SMS open rates quoted across the industry. Few trace back to a published primary source, so treat them with caution. The firmer difference is what each channel reports back. Meta's WhatsApp Cloud API returns sent, delivered and read statuses for each message through webhooks. SMS returns a delivery receipt from the network and nothing about whether the diner opened it.
Read rate is still a proxy. The measures that pay the bills are redemptions, bookings, return visits and revenue per send. Revenue per send is attributed revenue divided by messages sent. It works the same way for both channels, so it gives you a like-for-like comparison.
Return visits are where guest WiFi helps. When a diner logs back in to your guest WiFi, you have a record of the visit. Device identity alone undercounts returns, though. Purple's support documentation on MAC randomisation notes that iOS 18 now defaults to a rotating address that changes every two weeks. A consented login identity, such as a mobile number or email address, stays stable where a device address does not.
Consent: what UK GDPR, PECR and Meta each require
Both channels sit under the same UK law. PECR regulation 22 requires prior consent for marketing by electronic mail, which includes texts, unless the soft opt-in applies. UK GDPR Article 4(11) defines consent as freely given, specific, informed and unambiguous, given by a clear affirmative action. Recital 32 rules out pre-ticked boxes. Article 7 requires you to prove consent and make withdrawal as easy as giving it.
The soft opt-in lets you text a diner whose number you collected during a sale or negotiations for a sale. ICO guidance limits it to your own similar products. You must also offer a simple opt-out at collection and in every message.
WhatsApp adds a layer on top. Meta's WhatsApp Business Messaging Policy requires opt-in permission before you message someone, and you must honour requests to stop. GDPR consent must be specific, so ask for SMS and WhatsApp separately rather than bundling them. A tick for texts is not a WhatsApp opt-in.
Template rules: Meta's approval step versus SMS character limits
Outside the 24-hour service window, WhatsApp only lets you start a conversation with a Meta-approved template. Each template falls into one of three categories: marketing, utility or authentication. A weekend offer is marketing. A booking confirmation is utility. Meta can re-categorise a template it judges to be promotional, which changes its price.
Templates can carry variables such as first name and booking time, an image header and buttons. Meta also limits how many marketing templates one person receives from businesses, based on that person's engagement. Some sends will therefore not deliver, even to opted-in diners. New numbers also start with a cap on unique recipients per rolling 24 hours, which rises as your quality rating holds.
SMS has no approval step, so a "tables free tonight" text can go out in minutes. The constraint is length. A single text carries 160 characters in the GSM-7 alphabet, or 70 once you add an emoji. Longer messages split into segments of 153 or 67 characters, and each segment is billed. An alphanumeric sender ID shows your venue name, but diners cannot reply to it.
When is WhatsApp the right call for a restaurant?
WhatsApp earns its cost when the message needs more than a line of text, or when the diner is likely to reply.
- Your guests already message you on WhatsApp. Free-form replies inside the 24-hour service window carry no charge. Utility templates sent inside an open window are also free, per Meta's pricing documentation.
- You run click-to-WhatsApp ads. When a diner messages you from a click-to-WhatsApp ad or a Facebook Page button, and you reply within 24 hours, all messages are free for 72 hours.
- The offer sells on a picture. A photo of the new tasting menu in an image header does work that 160 characters of text cannot.
- Your messages run long. A 600-character menu update costs one template on WhatsApp. On SMS, the same text needs four GSM-7 segments.
- You need to see reads, not just deliveries. Read statuses let you separate a message nobody opened from a message that was read but did not convert.
- Booking changes happen in conversation. A diner can reply "can we make it 8pm?" and your team can answer in plain language, inside the free window.
For a full set-up checklist, including opt-in wording, see WhatsApp marketing for hotels: opt-in rules and a setup checklist.
When is SMS the right call for a restaurant?
SMS is the dependable default for short, urgent offers to a broad UK list.
- Your list spans every kind of handset. SMS reaches diners without WhatsApp, without data and without a smartphone.
- Speed beats polish. A quiet Tuesday or a cancelled large booking needs a text out within minutes. There is no Meta template to draft, submit and wait on.
- The message fits in 160 characters. A short, emoji-free offer costs one segment per diner, which is the cheapest unit either channel offers.
- You rely on the soft opt-in. PECR allows marketing texts to diners whose numbers came from a sale, under strict conditions. Meta's policy still requires explicit WhatsApp opt-in.
- You run lean. SMS needs no Meta business account, display name review or template approvals.
If you are also weighing email, SMS vs email for pubs and bars: which channel brings guests back covers that comparison.
What does each channel cost per message?
Neither channel has a single national price, so compare structure first, then plug in your quotes.
How WhatsApp pricing works
Since 1 July 2025, Meta charges per delivered template message. The rate depends on the recipient's country code and the template category. Marketing templates carry a higher rate than utility templates in Meta's published rate card. Service messages, meaning your free-form replies inside the 24-hour window, are free. Most businesses also pay a fee to the provider that runs their WhatsApp Business account.
How SMS pricing works
Your SMS provider sets a rate per segment, which varies by destination. Message length and character set decide how many segments each text uses. One emoji or one pasted smart quote switches the whole message to Unicode. That cuts a segment from 160 characters to 70.
| Cost line | SMS | |
|---|---|---|
| Unit billed | Delivered template | Segment sent |
| Rate set by | Meta rate card, by country and category | Your provider's rate card |
| Effect of length | None up to 1,024 characters | Each extra 153 GSM-7 or 67 Unicode characters adds a segment |
| Free messages | Service replies in window; utility templates in open window; 72-hour ad entry window | None outbound |
| Cost per send | Delivered templates × category rate + provider fee | Recipients × segments × rate |
Worked scenario: a four-site pizza group trims its SMS bill
Situation. A four-site pizza group sends a weekly offer by SMS to 8,000 opted-in diners. The message runs to 210 characters and opens with a pizza emoji.
What they did. The emoji forces Unicode, so 210 characters split into four 67-character segments. That is 32,000 billable segments per send. The team removed the emoji, which brought the text back to GSM-7 and two segments. They then cut the copy to 158 characters, which fits in a single segment.
Outcome. Billable segments fell from 32,000 to 8,000 per send, a 75% reduction, with the same list and offer. Over 52 weekly sends, that removes 1,248,000 segments from the annual bill. The comparison with WhatsApp then becomes fair: 8,000 single-segment texts against Meta's UK marketing rate for each delivered template.
Worked scenario: a 120-room hotel restaurant moves booking messages to WhatsApp
Situation. A 120-room hotel's restaurant handles 400 bookings a week. On SMS, each booking gets a confirmation and a same-day reminder. Every reply to a change request is another outbound text.
What they did. The hotel invited guests to book by messaging its WhatsApp number. A guest's message opens the 24-hour service window, so the confirmation goes out as a free utility template. Staff answer change requests with free-form replies, which are also free. Only the same-day reminder, sent outside the window, is a paid utility template.
Outcome. Billable messages fall from at least 800 texts a week to 400 utility templates, a 50% reduction. That figure excludes change replies, which add to the SMS count but cost nothing on WhatsApp. The hotel kept SMS as a fallback for guests without WhatsApp.
How do you build an opted-in list for either channel?
Cost per message is irrelevant if the list is thin. Most CRM tools assume the list exists. For a physical venue, it rarely does.
Purple Engage builds the list from people who are already in your venue. Diners log in to your guest WiFi and make a conscious-choice opt-in at sign-up. The result is consented, first-party data you own, collected at the moment the diner is at your table. Purple recorded 440 million logins in 2024 across 80,000+ live venues, according to Purple's own data. Hospitality brands including Pizza Express and Stonegate Pubs run Purple guest WiFi.
Purple is hardware-agnostic and runs as a cloud overlay. It works with Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet access points. You keep the hardware you own.
Once diners are on the list, LogicFlow decides what happens next. It can trigger email campaigns, surveys and text alerts from any data, from a diner's age to the weather outside. It can also send data to a third-party platform, such as the provider behind your WhatsApp Business account. LogicFlow requires an Engage licence; the LogicFlow v2 support article covers set-up.
Purple is certified to ISO 27001 and Cyber Essentials, and is GDPR compliant and a certified B Corp. Read the Product overview for what each Engage plan includes.
How should you decide for your venues?
Work through these five steps before you commit budget to either channel.
- Audit your consent. Count how many diners have SMS consent, WhatsApp consent, or both. Your reachable list per channel is the number that matters, not total contacts.
- Sort your messages by type. Separate marketing offers from booking confirmations and reminders. Utility messages are cheaper on WhatsApp and often free inside an open window.
- Price one real send each way. Use your actual message, your actual list and both formulas in the cost table. Count segments honestly, including emoji and smart quotes.
- Test on revenue per send. Run the same offer on both channels to matched groups for four weeks. Compare redemptions, bookings and return visits, not opens.
- Set a default and a fallback. Most groups land on one channel for marketing and the other for bookings, or WhatsApp first with SMS fallback. Write the rule down so every site follows it.
Start capturing separate consent for both channels at guest WiFi login now. Even if you launch only one channel this quarter, you keep the option to add the second without rebuilding your list.
Frequently asked questions
Is WhatsApp cheaper than SMS for restaurant marketing?
Not always. WhatsApp charges once per delivered template, whatever its length up to 1,024 characters, so it suits long messages and two-way conversations. SMS charges per segment, so a short, emoji-free offer under 160 characters can cost less than a WhatsApp marketing template. Compare Meta's current UK marketing rate with your SMS provider's segment rate, multiplied by segments per message, before you switch any budget.
Can I send WhatsApp offers to diners who opted in to SMS?
No. Meta's WhatsApp Business Messaging Policy requires opt-in permission for WhatsApp messages, and UK GDPR expects consent to be specific to what the diner agreed to. An SMS opt-in does not extend to WhatsApp. Ask for each channel separately at sign-up and record when and how consent was given. Give diners an easy way to withdraw on either channel.
Does Meta have to approve every WhatsApp message I send?
No, only the templates. Any message that starts a conversation outside the 24-hour service window must use a Meta-approved template, reviewed before first use. Once approved, you can reuse it with variables such as first name or booking time. Free-form replies inside an open service window need no approval, so your team can answer booking questions in plain language.
Can Purple Engage build my SMS and WhatsApp list from guest WiFi?
Yes, Purple Engage builds a consented, first-party list from guest WiFi logins, with conscious-choice opt-ins captured at sign-up. LogicFlow, which requires an Engage licence, can trigger email campaigns, surveys and text alerts from that data. It can also send data to a third-party platform, such as your WhatsApp Business provider. Collect separate consent for each channel you plan to use.
Will Purple work with the WiFi hardware my venues already have?
Yes. Purple is hardware-agnostic and runs as a cloud overlay on Cisco Meraki, HPE Aruba, Ruckus, Juniper Mist, Ubiquiti UniFi, Cambium, Extreme and Fortinet. You keep the access points you own and add Purple guest WiFi on top. List building can start without replacing hardware across your estate.
Can I use the soft opt-in to text diners who have booked a table?
Only if every PECR condition is met. The soft opt-in covers contact details collected during a sale or negotiations for a sale, for marketing your own similar products. You must offer a simple opt-out when you collect the number and in every message after. The soft opt-in does not meet Meta's WhatsApp opt-in requirement, so WhatsApp still needs explicit permission.
What happens if diners block or report my WhatsApp number?
Your sending can be restricted. Meta gives each business phone number a quality rating based on recent recipient feedback, including blocks and reports. A low rating can stop your messaging limit from rising, and Meta can pause templates that draw poor feedback. Send only to opted-in diners, keep offers relevant, include a marketing opt-out button, and honour stop requests promptly.
Do I need to replace Mailchimp or Klaviyo to use Purple Engage?
No. LogicFlow can send data to a third-party platform, so consented contacts captured at guest WiFi login can flow into the tools you already run. The difference is the source of the list. Mailchimp and Klaviyo send to contacts you already hold, while Purple Engage builds the list from diners who log in at your venues.