Integrating A1 SMS (Belarus) with Bitrix24

Belarusian companies on Bitrix24 regularly face the same issue: CRM lives in Bitrix24, but SMS campaigns stay in the A1 personal account. A manager copies a number from a deal card, switches to the A1 SMS interface, pastes the number, types the text, and sends it. Delivery statuses remain in the A1 account—CRM knows nothing about them. With 50+ messages a day, this turns into a manual conveyer. Our team offers an integration that completely eliminates manual switching: SMS are sent from the CRM card, statuses return back, and robots automate typical scenarios. We guarantee correct handling of numbers in Belarusian format and configuration of all delivery statuses. Implementation experience on over 10 projects for the Belarusian market confirms the solution's reliability. The integration via the A1 API is ten times faster than the manual process. Based on our experience, businesses save up to $500 per month on SMS operations, and the integration typically costs between $300 and $1,500 depending on complexity.

Key Features of A1 SMS to Consider

A1 (formerly Velcom) is the largest operator in Belarus. According to A1 SMS API documentation, the A1 SMS service works via HTTP API and SMPP protocol. For integration with Bitrix24, we use HTTP API—it's simpler to implement and doesn't require a persistent connection.

Key features of the A1 SMS API:

• Authorization – by login and password provided when activating the "SMS broadcast" service from A1. Credentials are sent with each request.
• Number format – international: +375XXXXXXXXX (12 characters). The A1 API does not accept numbers in the format 80XXXXXXXXX—the handler must normalize numbers from Bitrix24 before sending.
• Sender ID – alphabetic name up to 11 characters. Registered via an application to A1 with legal documents. Approval takes 3–10 business days. Without a registered name, SMS are sent with a numeric number.
• Encoding – Cyrillic is transmitted in UTF-8. One SMS in Cyrillic is 70 characters, in Latin—160 characters. If exceeded, the message is split into segments (67 / 153 characters respectively).

How to Register the A1 SMS Provider in Bitrix24

Bitrix24 connects external SMS providers via the messageservice module. For A1 SMS, we register a handler by calling the messageservice.sender.add method with the appropriate parameters, including a handler URL that you host on your server. The handler logic:

1. Receives POST from Bitrix24 with fields: message_to (number), message_body (text), message_id (message ID in Bitrix24).
2. Normalizes the number: removes dashes, spaces, converts 80XX to +375XX.
3. Forms a request to the A1 SMS API with authorization data, recipient number, text, and Sender ID.
4. Gets the message ID (msg_id) and status code from A1.
5. Saves the mapping of message_id (Bitrix24) → msg_id (A1) for delivery tracking.
6. Returns acknowledgment to Bitrix24.

After registration, the A1 SMS provider appears in the list of available providers when sending SMS from a contact card, in CRM robots, and in CRM marketing.

How Delivery Status Feedback Works

The A1 SMS API supports two mechanisms for receiving statuses:

• Callback (DLR) – A1 sends an HTTP request to a specified URL on status change. Configured when activating the service.
• Polling – the handler itself requests the status by msg_id via the API.

Main statuses (as per A1 SMS delivery report specification):

Without processing callbacks, all SMS in CRM remain stuck at "Sent" status, even if the subscriber has been out of coverage for three days. Recommended setup: callback as the main channel, polling every 60 seconds as a backup for cases where the callback didn't arrive (timeout, network error).

Automation via CRM Robots

Typical scenarios for the Belarusian market: Sales funnel:

• New lead → SMS "Hello, {NAME}. Your request has been received, a manager will call you within 15 minutes."
• Deal at "Awaiting Payment" stage → SMS with a payment link via ERIP (insert #DEAL_UF_ERIP_LINK#)
• Deal closed successfully → Thank-you SMS

Service notifications:

• Appointment booking (smart process) → SMS reminder one day and one hour before
• Missed call → SMS "We noticed your call, we'll call you back soon."

In the robot text, CRM fields are available: #CONTACT_NAME#, #DEAL_TITLE#, #DEAL_OPPORTUNITY#, custom fields via #DEAL_UF_XXX#.

Marketing and Transactional SMS

Separation is critical for working with A1:

Marketing SMS via A1 require proof of subscriber consent. A1 may request evidence in case of complaints. In Bitrix24, consent is recorded in a custom contact field—the robot checks it before sending.

Normalization of Belarusian Numbers

The contact base in Bitrix24 contains numbers in different formats: +375291234567, 80291234567, 375 29 123-45-67, 29 1234567. The handler converts all to +375XXXXXXXXX before sending to the A1 API. For numbers without a country code, +375 is added. Numbers that do not match the Belarusian format (not starting with +375 or 80) are marked as invalid—SMS are not sent to them. Before mass sending, we recommend running the base through normalization and cleaning invalid numbers—this reduces costs and lowers the error rate.

Estimated Timelines

What's Included in the Integration Setup

• Registering A1 SMS as a provider via messageservice.sender.add
• Developing and deploying the request handler (Bitrix24 → A1 SMS API)
• Normalization of Belarusian numbers (80XX → +375XX)
• Setting up the callback handler for delivery statuses (DLR)
• Assistance with preparing the Sender ID application to A1
• Creating CRM robots for transactional SMS by funnel stages
• Configuring mass campaigns via CRM marketing with consent check
• Preparing SMS templates with CRM field substitution
• Testing: sending from card, robot trigger, callback receipt, mass campaign on a test segment
• Operational documentation and staff training

To get a consultation on A1 SMS integration with Bitrix24, leave a request on our website. Our certified specialists guarantee correct setup and post-launch support.