SMS or WhatsApp Business? A neutral comparison for businesses in Germany
SMS or WhatsApp Business for customer messages in Germany: reach, opt-in rules, pricing models, template approval, delivery without an app and GDPR compared.
WhatsApp is on most smartphones in Germany, and many businesses ask whether they should send order updates, reminders and offers there instead of by SMS. We sell SMS, so take this comparison with that in mind; we have tried to write it so that it would also be useful if you end up choosing WhatsApp. The short answer: the two channels solve different problems, and for many companies the right setup uses both.
Two products called WhatsApp Business
“WhatsApp Business” means two different things, and the difference matters for everything below:
- The WhatsApp Business app is a free app for small businesses. One phone, a business profile, manual chats, some quick replies. It is not built for automated messages from a shop or booking system.
- The WhatsApp Business Platform (often called the WhatsApp API) is what you need for automation. You access it through Meta directly or through a Business Solution Provider, verify your business, and send messages from your software. This is the product that competes with an SMS gateway, and the rest of this article refers to it.
The comparison at a glance
| SMS | WhatsApp Business Platform | |
|---|---|---|
| Reach | Every mobile number, every phone, no app, no data connection | Only recipients who use WhatsApp on that number |
| Setup | Account, API key, sender name; in Germany no registration of the name | Business verification, approved display name, provider contract |
| Content | Text, 160 GSM characters per segment, links | Text, images, documents, buttons, longer messages |
| Business-initiated messages | Free text, no approval | Only pre-approved templates |
| Replies | Not possible to an alphanumeric sender | Two-way chat is the core feature |
| Pricing | Per segment, the same for every kind of message | Set by Meta per message category and country, plus provider fees |
| Status | Delivery report | Delivered and read |
Reach: the app is the precondition
An SMS reaches every active mobile number: smartphones, basic phones, company phones, phones abroad with roaming, phones without mobile data. WhatsApp reaches only people who have installed it and registered the same number you have on file. In Germany that is a large share of consumers, but not everyone: some people do not use WhatsApp at all, many company phones block it for data-protection reasons, and customers sometimes give you a landline or a second number. A WhatsApp message to a number without WhatsApp simply cannot be delivered. For anything that must arrive, a WhatsApp setup therefore needs an SMS fallback.
Opt-in: two layers of rules
For SMS, German law distinguishes clearly. Transactional messages that are part of a contract, such as order confirmations, shipping notices or appointment reminders, need no advertising consent. Advertising by electronic mail, which includes SMS, requires the prior express consent of the recipient (§ 7(2) no. 2 UWG), with a narrow exception for similar products to existing customers who were told they can object at any time (§ 7(3) UWG). Our article on SMS and GDPR explains this in detail.
For WhatsApp, the same German rules apply to advertising, because WhatsApp messages are generally treated as electronic mail. On top of that come Meta’s own business policies: you need the person’s opt-in to receive messages from your business on WhatsApp, and Meta can restrict or block accounts whose messages are reported or blocked too often. In practice this means a separate WhatsApp opt-in in your checkout or booking form, even for transactional messages, because a phone number given for delivery is not the same as permission to write on WhatsApp.
Cost model: per segment or per category
SMS pricing is simple: you pay per segment, and the price depends only on the destination country. With TopSMS a message to Germany or Austria costs €0.084 per segment, whether it is a code, a shipping notice or a campaign, with no monthly fee. The variable you control is the length: stay within 160 GSM characters and each message is one segment.
WhatsApp pricing is set by Meta and depends on the category of the template (marketing, utility, authentication) and on the recipient’s country. Marketing messages are the most expensive category. Meta has changed the billing unit in the past, from 24-hour conversations to individual template messages, and it adjusts rates regularly, so check Meta’s current pricing page before you calculate. Replies within the customer service window, the period after a customer has written to you, are treated differently from business-initiated messages. Most providers add their own platform fee or a margin per message. A fair comparison therefore needs your real mix of message types and the provider’s full price, not only Meta’s list price.
Templates and approval
With SMS you write any text and send it; the rules are legal ones, enforced afterwards. With the WhatsApp Business Platform, every message you start (outside the customer service window) must use a template that Meta has reviewed and approved, assigned to a category. Variables such as the order number are allowed; changing the wording means a new review. Approval is often quick, but templates can be rejected or recategorised, for example when a “utility” message contains promotional content. For one-off, time-critical messages, such as “the practice is closed today”, this review step is a real limitation.
Delivery without an app or a data connection
SMS travels over the mobile network’s signalling channel. It arrives in places with poor coverage, without mobile data, while roaming with data switched off, and on phones that are years old. WhatsApp needs an internet connection on the recipient’s side; a phone without data receives the message only when it is back online. For verification codes and urgent notices this difference is often decisive, which is why many services that offer WhatsApp codes keep SMS as the fallback.
GDPR considerations
With both channels you are the controller and need a legal basis for processing the phone number (Art. 6 GDPR), typically the contract for transactional messages and consent for advertising. The differences lie in who else processes the data:
- SMS through an EU gateway: the gateway is your processor under a data processing agreement (Art. 28 GDPR), and the data can stay in the EU. TopSMS runs in an EU data centre, delivers through EU-based carriers and publishes its DPA.
- WhatsApp Business Platform: Meta and usually a Business Solution Provider are involved. Check the data processing terms of both, where the data is processed and which transfers outside the EU take place, and document this in your records of processing and privacy notice.
- WhatsApp Business app on a company phone: the app can access the address book of the phone. Data protection authorities have repeatedly criticised this for business use, because it can transmit numbers of people who never agreed to it. Many companies therefore keep WhatsApp off company phones entirely.
None of this makes WhatsApp unlawful, but it means more documentation and a closer look at the contracts. This is general information, not legal advice.
When which channel fits
- Verification codes: SMS for universal reach; WhatsApp as an option for users who prefer it.
- Order and shipping notices, appointment reminders: SMS reaches everyone without a separate opt-in; WhatsApp works well if customers chose it and you keep SMS as the fallback.
- Customer service and conversations: WhatsApp, because two-way chat is what it is built for.
- Marketing with images and buttons: WhatsApp offers more format, at a higher price per message and with stricter opt-in; SMS is cheaper per contact and reaches people who do not use WhatsApp.
- Urgent one-off messages to everyone: SMS, because no template approval is needed.