SMS is a reliable and staple channel for brands to use when connecting with their customers. But when should brands use inbound vs. outbound SMS messages? In this blog we’ll walk through the ins and outs of inbound and outbound SMS to ensure brands get the most out of every campaign.
What are inbound SMS messages?
What are outbound SMS messages?
Inbound vs. outbound SMS: Key differences
Of course, the main difference between outbound and inbound SMS is the intended action of the customer. With inbound SMS, the customer sends a message, initiating a two-way SMS conversation. With outbound SMS the business is the only sender, usually sending mass SMS or bulk SMS messages to a large group of customers. Let’s run through the other key differences between the two, and how to know when to use each method for marketing campaigns.
Inbound SMS
- Conversation starter: Customer initiated
- Objective: Engagement and feedback collection
- Sender type: 10DLC, VLN, short codes
Benefits of inbound SMS:
- Boost customer engagement: Customers are the conversation starters with inbound SMS meaning their interest to engage with your brand is higher with inbound use cases
- Better lead qualification: Customers that reach out to your brand through an inbound SMS campaign show instant interest by taking that first step, making them a higher qualified lead
- Two-way communication: Since customers can chat with your brand, you can support customer service, inquiries, and chatbot interactions, creating a seamless experience
- Real-time feedback: Brands can collect more information from customers in their own words with feedback surveys and SMS interactions that they otherwise wouldn’t collect
- Cost effective: SMS is a cost-effective two-way communication channel that brands can use to connect with customers and cut costs while still reaping great results
Best practices for inbound SMS:
- Use a clear and simple CTA to make it easy for customers to understand how to engage with your brand. For example: “Text JOIN to 1234 to get access to special discounts!”
- Offer instant gratification as an incentive to engage with your brand and sign up for marketing messages. For example: “Text BIG10 for 10% off your first purchase!”
- Ensure fast responses with an SMS chatbot or automated replies so your customer isn’t waiting for a response to their inbound SMS
- Track and analyze important data like engagement rates, keyword performance, and number of messages exchanged in a single conversation to optimize future interactions
Inbound SMS use cases:
- Customer support via SMS chat
- Keyword-based promotions – ie., “Text WIN to 12345 for a chance to win!”
- Survey and feedback collection
Inbound SMS campaign example:
Wefarm is a digital platform for small-scale farmers to connect, access education, and a wide range of resources to help them grow their businesses. Wefarm used two-way SMS campaigns to give farmers easy access to answers to FAQs, share knowledge, and access farming inputs.
Outbound SMS
- Conversation starter: Brand initiated
- Objective: Notify or alert customers, promote products and services
- Sender type: Alphanumeric, short codes, 10DLC, toll-free numbers
Benefits of outbound SMS:
- Proactive engagement: Brands can reach out to targeted customers with personalized messages that are relevant and engaging for them
- High open rate: SMS has a very high open rate at 98%, meaning outbound marketing messages get excellent visibility
- Scalability: SMS is a channel available on all mobile phones worldwide, making it easy to scale up bulk SMS messages as your campaigns grow
- Improved retention: With regular reminders, alerts, notifications, and relevant promotions, outbound SMS can help boost customer retention rates
- Automated and efficient: SMS is an easy channel to integrate into any tech stack, CRM, or other tools brands are using, making it a simple and efficient solution for automated bulk messaging
- Boost conversions: With relevant promotions and special offers, customers are incentivized to convert and complete purchases
Best practices for outbound SMS:
- Make sure you have explicit consent from customers to send them outbound SMS messages with SMS opt ins, keeping your messages compliant. Also ensure you provide clear opt-out instructions if customers decide they don’t want to receive SMS messages anymore.
- Segment and target specific audiences with the right promotion or offer to keep them engaged with relevant and personalized SMS. You can do with a customer data platform and customer engagement solution – creating various message campaigns that are sent to the right audience. ”
- Carefully limit the frequency of your SMS messages. You don’t want your brand to be flagged as spam or to be perceived as annoying to the customer. Send strategic and relevant SMS messages at the best time.
- Use A/B testing on marketing campaigns to understand which messages have the best click through rates, conversion rates, and other metrics to optimize future campaigns.
Outbound SMS use cases:
- Flash sales and promotions
- Appointment reminders
- Delivery and transaction updates
Outbound SMS campaign example:
A leading wholesale business used outbound SMS messages to send coupons to their customers. After two weeks, they would send another SMS blast as a reminder to use the special offer before it expires.
What works for you: Inbound or outbound SMS?
So, how do you know when to use each SMS strategy? There are a few things to consider. First, what is the goal of your messaging campaign?

Inbound SMS goals
- Boosted engagement rates
- Improved satisfaction with support
- Collect more accurate feedback
- Lead generation
- Loyalty program enrollment

Outbound SMS goals
- Drives sales and conversions
- Customer retention
- Reduce no-shows to appointments
- Improved satisfaction with delivery
- Boost re-engagement
Understanding what your brand wants to achieve will help you narrow down how to build your SMS messages and what you’ll need for the best results. Inbound SMS is ideal for brands that want to interact more with customers, whether that’s to get more feedback, improve engagement and loyalty with their brand or gain more leads, receiving messages from customers is the best way to achieve this.
On the other hand, outbound SMS is perfect for brands that want to send bulk SMS messages to a wider audience, these can still be personalized and relevant, don’t require a response from customers, but aim to encourage them to complete an action like completing a purchase with a discount code or showing up to appointments thanks to reminders.
Now, depending on your industry, your choice of inbound or outbound SMS might change as well. Let’s walk through some industry-specific examples that can help you decide:
Retail and eCommerce
When to use inbound SMS
Customers ask about when they can expect their order.

When to use outbound SMS
Send a message with a discount code to promote a limited time offer.

Healthcare
When to use inbound SMS
The patient of a chiropractor uses a SMS keyword to sign up for an appointment wait list.

When to use outbound SMS
A clinic sends patients appointment reminders via SMS to reduce no-shows.

Banking and finance
When to use inbound SMS
A client sends an SMS keyword to find out their account balance.

When to use outbound SMS
An SMS informing customers about policy changes on their credit card.

Telcos
When to use inbound SMS
A customer sends an SMS to top-up their data plan.

When to use outbound SMS
Send a reminder to customers who have outstanding payments.

Travel and hospitality
When to use inbound SMS
A customer sends a review for the hotel via SMS.

When to use outbound SMS
A welcome message that gives the guest a discount at the spa.

How to set up inbound and outbound SMS campaigns
You can make quick and easy work out of setting up your SMS campaigns on the Infobip Portal for both inbound and outbound SMS. Here’s a quick guide on how to do it:
1. Create an Infobip account:
Sign up for an account on the Infobip platform and log in to your account. This will provide access to the dashboard where you can manage your SMS campaigns.
2. Set up outbound SMS campaigns:
- Contact List: Import or create a list of recipients for your campaign. Ensure compliance with consent regulations
- Message content: Draft your SMS message, keeping it concise and engaging. You can use Infobip tools like Moments or People to help personalize the message
- Schedule and send: Choose when to send your messages. Infobip allows immediate sending or scheduling your messages to be sent later
- Track and analyze: Use the Infobip analytics tools to monitor delivery reports, open rates, and engagement metrics
3. Configure inbound SMS:
- Sender Type: Purchase or set up the appropriate sender type (number) through Infobip to receive inbound messages
- Keyword management: Define keywords for auto replies and routing. This helps in managing responses based on the user’s inbound message
- Automated responses: Set up automated workflows to respond to inbound messages or route messages to the appropriate department
4. Use API for integration:
You can, alternatively, integrate Infobip’s SMS API within your existing tech stack to program and manage your SMS messages. You can sign up for free and get an API key and base URL to get started.
5. Ensure messages are compliant:
Adhere to regulations like GDPR or TCPA by managing consents for outbound messages and providing opt-out options for recipients.
6. Test your campaigns:
Before launching, test your inbound and outbound campaigns to ensure everything functions as expected in terms of delivery and response handling.
7. Optimization:
Use insights from reports to refine message content, timing, and targeting for better results in future campaigns.
FAQ’s about inbound and outbound SMS
With inbound SMS, the customer initiates the conversation with a brand, and it typically involves customer support, opt-in for marketing messages, or keyword campaigns. The intent is for the customer to participate in a two-way conversation.
Outbound SMS is when brands send customers proactive messages for promotions, special offers, or appointment reminders. The intent is to prompt the customer to complete an action.
Inbound SMS campaigns are built to improve engagement because the customer is interacting directly with the brand over SMS.
Outbound SMS messages can be slightly more costly than inbound SMS campaigns – but not always. The cost can vary based on location and volume of messages. Inbound SMS can be lower in cost, but businesses might be charged fees based on service set up. For businesses, especially those using bulk messaging services, outbound messages generally are the main cost to consider.
Ultimately, if you are managing costs for SMS services, it’s essential to thoroughly review the pricing structure and terms of service provided by your telecommunications provider or SMS provider to understand the specific cost dynamics involved for both inbound and outbound messages.
Both campaigns need to be in line with messaging regulations and regional SMS compliance laws. When the customer initiates a conversation with an inbound campaign, this is considered implied consent. The customer has opened the conversation, and the brand is free to respond appropriately. Before sending outbound messages, brands need to collect explicit consent from customers to add them to SMS lists.
In both instances, the brand needs to adhere to the parameters of the messages the customer has consented to receiving. That means if a customer sends a customer support inquiry via SMS, that brand cannot start sending marketing messages.
For both inbound and outbound SMS, brands need to provide clear opt-out instructions in case the customer does not want to receive these messages anymore.
Outbound SMS messages are not designed to prompt a response from customers.
Response rates are important for inbound SMS campaigns since the goal of the interaction is to engage with the customer.
Yes! Brands can use both inbound and outbound strategies for different use cases depending on the goal and desired outcome of the interaction.
Inbound SMS is better for customer support since the customer can report their issue and work through their inquiries with a brand through a two-way conversation.
Outbound SMS is one-sided and not ideal for customer support.
Brands should conduct A/B testing on outbound SMS messages to determine which CTAs, messages, and segments perform the best. Some metrics to track include open rates, conversion rates, and click-through rates to optimize future campaigns.
Inbound SMS campaigns should track engagement rates, response rates, and customer satisfaction to accurately measure the success of the two-way conversations and optimize responses.