Quick Answer:
There is no single best channel between Email, SMS, and WhatsApp. Email works best when customers need detail and context, SMS when information is short and time-sensitive, and WhatsApp when the communication benefits from conversation or a response.
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Email vs SMS vs WhatsApp: Which Channel Should You Use and When?
The right choice depends on what you’re communicating, who you’re communicating with, how urgent the message is, and what you need the customer to do next.
A one-time password and a detailed onboarding guide are distinct communication needs, so they require different channels that provide enough room to convey the message effectively.
So, before you make any choice between Email, SMS, and WhatsApp, here are a few factors you should consider:
How urgent is the information?
If the customer needs to see the message quickly, a channel suited to immediate notifications may be more appropriate than one that requires the customer to sit down and read through a longer message.
How much information does the customer need?
Some messages can be understood in a few words. Others need context, instructions, links, or additional information that the customer may want to revisit later.
Does the customer need to respond?
There is a difference between telling a customer that their order has shipped and giving them a place to ask a question about that order. The purpose of the interaction can influence the channel you choose.
What do you know about the customer?
A new customer, a repeat customer, and someone who has not interacted with your business in months may need very different communication, even if they all appear in the same contact list.
Where is the customer in their relationship with your business?
The communication that was valuable during onboarding may not make sense after purchase, during retention, or when you’re trying to reactivate an inactive customer.
Check out this guide for more detail on different phases of a customer journey: Customer Lifecycle Marketing,
And perhaps one of the most important questions:
What action has the customer carried out?
You can sometimes create a poor communication experience for your customers if you ignore an action that they have taken.
For example, if an online store sends a customer an Email confirming their order. A few hours later, they send the same information by SMS and then repeat it on WhatsApp. There might be no issue with this, unless for one thing. If the customer has already received and acted on the information, sending it again simply because another channel is available may add more noise than value.
Once you approach communication this way, Email, SMS, and WhatsApp will no longer look like competing channels. They become different tools for different communication needs.
The best channel, therefore, depends less on the channel itself and more on what you are trying to communicate, who you are communicating with, and what you need the customer to do next.
We explored this conversation in a recent webinar session with Mabel Adeteye, Head, Brand and Marketing Communications, Wema Bank Plc, where she shared her perspective on how changing customer expectations are influencing the way businesses think about communication.
Watch the full conversation on YouTube → Here
With that in mind, let’s look at when to use each channel and when combining them may be the better approach.
When Should You Use Email?
Email makes the most sense when the customer needs more than a quick update. If the message requires context, several pieces of information, or something the customer may need to come back to later, Email gives you the space to provide it properly.
Use Email when you are:
- onboarding a new customer
- explaining how a product or service works
- sharing educational content
- sending a newsletter
- providing detailed order or account information
- nurturing a prospect over time
- communicating an offer that needs more explanation
For example, a customer who has just subscribed to an online learning platform may need information about their account, how to access their courses, what to expect next, and where to find additional resources. Email gives enough space for you to communicate all necessary information about the course.
Email also becomes useful when communication forms part of a longer relationship with the customer. In this case, you can use it to educate a new subscriber, guide a first-time customer through onboarding, and continue providing relevant information as the relationship develops.
Also read: How To Create Engaging Email Campaigns
When Should You Use SMS?
SMS is useful when the message needs to reach the customer quickly and doesn’t require much explanation.
Its strength is its simplicity. You don’t need several paragraphs to tell someone that their payment was successful, their appointment is tomorrow, or their order is ready for delivery.
SMS is best for:
- OTPs and verification codes
- payment alerts
- appointment reminders
- delivery updates
- account notifications
- time-sensitive announcements
- short promotional messages
- important service updates
With SMS, you have limited space, so it works best when the message can remain clear and useful without a long explanation. If the customer needs instructions, background information, or an opportunity to explore several details, another channel may be more appropriate.
Bulk SMS in Nigeria for Customer Acquisition, Engagement and Retention explores how you can use SMS for strategic customer communication across the customer journey with your business.
When Should You Use WhatsApp?
WhatsApp becomes particularly useful when the communication needs room for interaction. Unlike a message that simply provides an update without any opportunity for feedback, WhatsApp gives your customer the chance to respond, ask a question, or continue the conversation with the business.
That makes it useful for:
- customer support
- order and delivery updates
- product enquiries
- appointment communication
- conversational marketing
- follow-ups
- reminders
- customer engagement
For example, a customer has just received a message that their order is ready for delivery. If they need to know that the order is on its way, an SMS might be enough. But if the customer may need to confirm a delivery detail, ask a question, or speak to someone, WhatsApp can provide a more appropriate environment for that interaction.
However, you shouldn’t assume that every customer communication should move to WhatsApp simply because customers use it frequently.
One question you must always ask is: Would this communication be better as a conversation?
If the answer is yes, WhatsApp may be the better choice.
Here’s a quick way to look at it:
| If the customer needs… | Consider… |
| Immediate, short information | SMS |
| Detailed information or something they may need to revisit | |
| A conversation or response | |
| Different types of communication at different moments | A coordinated combination |
These aren’t rigid rules. There will be situations where Email makes more sense for an urgent message, or SMS works better for something that isn’t particularly time-sensitive.
The point is to start with the customer’s need and work backwards to the channel, rather than choosing a channel simply because it’s available.
Having implemented all this, there is one important question you must ask. Which is:
When Should You Use Email, SMS and WhatsApp?
Using Email, SMS and WhatsApp together isn’t necessarily a bad idea. In fact, there are situations where using more than one channel can make the customer experience better. The problem is not having a clear purpose for your communication.
The point shouldn’t be to make sure every customer receives something through every available channel but to ensure using more than one channel adds value to the interaction.
So, when is it best to use multiple channels?
The customer needs different types of information.
A detailed confirmation and a short delivery alert are not the same message.
The communication happens at different points in the journey.
You might use Email during onboarding and SMS later for a time-sensitive reminder.
The customer needs to take different actions.
An Email might explain what to do, while WhatsApp provides a way to ask questions or get assistance.
One channel complements another.
An SMS could alert a customer to something that requires more information available in an Email.
If the customer has already completed an action, don’t keep sending reminders for it. If they’ve already received the information they need, another message may not improve the experience.
If you want to explore this idea in greater detail, check out omnichannel customer engagement strategy. It goes deeper into how businesses can create a connected customer experience across different touchpoints.
How do you know whether your Communication Strategy is working?
Choosing the right channel is only the beginning. You also need to know whether the communication is achieving what you intended. The easiest way to determine this is to look at the outcome.
If the goal was to get a customer to complete a payment, did they complete it? If you sent an appointment reminder, did they show up? If the purpose was to get a customer to respond, did they respond? If you were trying to bring an inactive customer back, did they return?
The right measure depends on the purpose of the communication.
You can look at metrics such as:
- Delivery and reach: Did the message successfully reach the customer?
- Engagement: Did they open, click, read, or respond where applicable?
- Conversion: Did the communication lead to the action you wanted?
- Response rate: Did customers respond when a response was part of the goal?
- Retention or repeat purchases: Did communication contribute to customers staying or buying again?
- Customer experience: Did the communication make the interaction easier, clearer, or more useful?
This also means that engagement alone doesn’t tell you whether a communication strategy is working. A message can generate opens, clicks or replies and still fail to achieve the business outcome it was designed for.
The same applies to channel selection. You may choose the channel that appears most appropriate, but if the message is irrelevant, the timing is poor, or the customer has already received the information, the channel cannot fix the underlying problem.
A strong communication strategy therefore puts these key factors into consideration: the message, timing, customer context, data, channel, and automation. More importantly, it connects those decisions to an outcome you can measure.
One of the important points Mabel Adeteye shared during our conversation was that customers don’t necessarily care about the tools or channels a business uses. What matters to them is the experience they have with the brand.
That puts channel selection into perspective. Before you communicate, you must understand what the customer needs and make deliberate decisions about how, when, and where to communicate with them.
Mabel also touched on the changing role of personalization, customer data and AI in modern communication, particularly the importance of using technology to improve communication without losing the human judgment required to keep communication relevant.
We’ve only touched on a few of those ideas here. If you’d like to hear Mabel’s perspective in full, you can watch the recorded conversation below.
Watch the full conversation with Mabel Adeteye on YouTube →
The conversation is a useful complement to this article, particularly if you’re thinking about how customer expectations should influence the way your business approaches Email, SMS, WhatsApp, automation, and your communication strategy.