SMS helps you reach employees wherever they work, including frontline and deskless employees who may not regularly access Haiilo, email, or other digital communication channels. You can use SMS messages in the Studio to deliver short, time-sensitive information directly to employees' mobile phones. Recipients only need a mobile network connection to receive the message.

SMS messages are delivered through Twilio, a third-party messaging provider connected to your Haiilo platform. You have to set up an account on Twilio to send SMS messages. Learn more in Setting up SMS for the Studio.

Understand recipient requirements

Haiilo uses the phone number stored in each user account's Mobile profile field to send SMS messages. You cannot select a different profile field for SMS messages.

Users must also actively agree to receive SMS messages by enabling SMS notifications in their notification settings. The option is disabled by default.

A user must meet all of the following requirements:

• The user is active.
• The user has enabled SMS in their notification settings.
• The user has a phone number in the Mobile profile field. Learn more about profile fields in Mapping profile fields.
• The phone number is valid and uses the E.164 international format, for example, +4917412345678. Phone numbers must start with +, include the country code, and contain no spaces.

Recipients who do not meet these requirements are excluded and do not receive the SMS message. Haiilo validates the selected audience and shows the number of valid recipients before the message is sent.

Understand characters and segments

SMS messages are divided into segments based on their length and the characters they contain. One message created in Haiilo can consist of multiple segments. Learn more about segments in Twilio's documentation.

The number of characters available in each segment depends on the characters used:

When a message exceeds the limit for a single segment, the character limit is reduced for all segments, including the first segment. For example, a GSM-7 message that requires multiple segments can contain up to 153 characters in each segment.

The recipient normally receives the segments as one combined message.

The Studio displays a character and segment counter while you write the message. Review the counter before sending, especially when targeting a large audience.

Understand SMS costs

Sending SMS messages incurs costs that are billed through your organization's Twilio account. The total cost can depend on factors such as:

• The number of valid recipients
• The number of segments in the message
• The sender number
• The recipients' destination countries
• Applicable registration or carrier fees

All costs incurred for sending SMS messages are billed to your Twilio account. These charges are managed by Twilio and are outside Haiilo's control. Your organization is responsible for reviewing and managing any costs associated with the use of the SMS service. Learn more on Twilio's Pricing page.

Understand delivery and replies

Recipients receive the message as a standard text message from the sender phone number you purchased in Twilio and entered in Haiilo's Administration. 

Sending the message does not guarantee that each recipient receives it. Delivery can depend on factors outside Haiilo, including:

• Whether the mobile phone number is correct
• Whether the recipient's device is switched on
• Whether the device is connected to a supported mobile network
• Carrier filtering or sender restrictions
• The configuration and status of the Twilio account

Recipients cannot reply to SMS messages sent from Haiilo, except by sending "STOP" to revoke their consent to receive SMS messages. 

Real-time delivery statuses and SMS analytics are not available in Haiilo. Delivery information and message logs are available in Twilio.