SMS for events: how to reach attendees who don’t use WhatsApp
When to use SMS and MMS at your event instead of WhatsApp, how to reach guests in the USA and how to handle every channel from a single dashboard.
SMS for events delivers alerts and answers to attendees who do not use WhatsApp. It is useful for reminders, attendance confirmations and last-minute changes. To answer questions, the service must be two-way: attendees reply in their own words and receive an answer using the event information.
Why include SMS
In the USA, 32% of adults say they use WhatsApp, up from 23% in 2021, according to the Pew Research Center [1]. 98% own a mobile phone of some kind and 91% own a smartphone [2]. SMS reaches their mobile with nothing to install.
At the events we work on in Europe, WhatsApp is usually the natural channel. But country alone is not enough to choose: ask each attendee which channel they prefer. This includes people who do not use WhatsApp without changing everyone else’s habits.
What to send by SMS and MMS
SMS carries text. MMS (multimedia messaging) adds an image inside the message, without having to open a link.
| Channel | Use at the event |
|---|---|
| Alerts and conversation with people who already use it | |
| Two-way SMS | Alerts, reminders and answers by text |
| MMS | Messages with an image, such as a ticket with a QR code or a venue map |
Choose the format based on what the attendee needs to receive. Text is enough to communicate a time; a photo may be more useful for showing a meeting point. If you need to send images to people who do not use WhatsApp, include MMS in the project configuration.
Three uses during the event
- Answer itinerary questions by SMS and send a photo of the transfer meeting point by MMS.
- Announce a room change through each attendee’s channel and use the updated information to answer subsequent questions.
- Collect feedback by SMS and combine it with WhatsApp replies in the client report.
For more on moving from sending messages to conversations with each attendee, see conversational AI communication for events.
What to prepare before the event
At registration, ask for a mobile number with its international prefix, consent to receive messages and a preferred channel. Also check which details you will share with the assistant: each attendee’s ticket, sessions or travel, depending on what the event needs.
Decide who keeps the information up to date and who steps in when a query needs a person. Every channel should use the same information, and your team should be able to view conversations in one place.
In the USA, businesses sending SMS from local ten-digit numbers, the system known as 10DLC, register their brand and how they will use the messages with The Campaign Registry through a provider. The brand is verified before it can send [3]. At Sinapser, we set up that connection with the client when configuring the project; it is best to start well ahead of the event.
If you are still choosing an assistant, see how to choose a chatbot for events.
How we do it with EVA
EVA (Event Virtual Assistant), our virtual assistant for events, supports WhatsApp, two-way SMS and MMS using the same event knowledge, depending on the project configuration. Your team sees the conversations in a single dashboard and can step in with the context in front of them.
If your registration platform passes it the QR code, EVA delivers it through each attendee’s channel; validation at the door stays in your registration system. The answers it collects with Objectives, what you specify that you want to know about attendees, reach the same results dashboard and report, whether they come from WhatsApp or SMS.
Common mistakes
Choosing the channel based only on country
Ask for a preference at registration. An attendee from the USA may also use WhatsApp.
Using send-only SMS to handle questions
Check that the service accepts replies. Attendees should be able to continue the conversation from the message they receive.
Separating information and feedback by channel
Keep a shared source for answers and bring feedback together in the same report. Your team needs to see what the whole audience is asking.
Sources
- Americans’ Social Media Use 2025, Pew Research Center (20 November 2025): 32% of US adults say they use WhatsApp, up from 23% in 2021.
- Mobile Fact Sheet, Pew Research Center (20 November 2025): 98% of Americans own a mobile phone of some kind and 91% own a smartphone.
- The Campaign Registry: in the US 10DLC system, brands register through a provider and are verified before they can send messages.
Frequently asked questions
Do I need two providers to use WhatsApp and SMS?
You can handle both channels with EVA. The choice depends on each attendee, and your team manages them from the same dashboard.
Can EVA answer by SMS using each attendee’s details?
Yes, depending on the data available. It can use their ticket, session and travel information to answer the question.
Where can I see how it works?
Visit the EVA page and personalised support for each attendee. For a demo based on your event, write to projects@sinapser.com with your audience’s countries and the registration platform you use.
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