“How much does a Viber bot cost?” has two answers: what Viber charges for traffic, and what the platform that runs the bot charges. This article separates the two, explains the session model that confuses most people, and walks through three realistic monthly bills. Current rates by country are on the Viber chat sessions page and in the pricing section; the numbers below describe the structure, not a quote.
What is free
- Registering the bot. Registration through an official partner is free. SMSBAT is a Rakuten Viber partner; the registration page lists what to prepare.
- Building the bot. The no-code builder and the shared inbox are included in the platform plan; there is no per-scenario or per-button fee.
- Customer-initiated sessions up to a monthly allowance. When a customer writes to the bot, the session that opens is free within the allowance Viber gives every bot each month. For a small business this allowance often covers all support traffic.
What Viber charges: sessions
Viber does not bill chatbots per message. It bills sessions. A session is a 24-hour window with one customer; every message inside it, in either direction, is included.
Two kinds of sessions exist:
- Customer-initiated: the customer writes first. Free up to the monthly allowance, then paid at a per-session rate.
- Bot-initiated: the bot writes first, for example a delivery notification, a reminder or a promotion to a subscriber. Paid from the first one.
The practical consequence: a support bot that mostly answers questions costs little, because most sessions are started by customers. A bot that sends marketing broadcasts to 20,000 subscribers costs 20,000 sessions each time, because every broadcast opens a bot-initiated session with every recipient. Broadcasts are still cheaper than SMS in Viber markets, but they are the line item to watch.
Session rates differ by country. Ukraine, Bulgaria, Greece and the Balkans are the cheapest tier; Western Europe costs more. The session counter in the SMSBAT panel shows the running count so there are no surprises at the end of the month.
What the platform charges
The platform fee covers the builder, the inbox, operator seats, integrations, reports and the API. SMSBAT prices this as a monthly plan; the pricing page has the tiers. Two optional add-ons are billed separately:
- AI operator: answers from your knowledge base before a human does. Priced per month by the number of inbound messages, with a free trial.
- Verification badge: a one-time request through the partner, described on the bot verification page.
Three worked examples
The figures use round session counts to show the structure; multiply by your country’s rates.
Online shop, 3,000 customer questions a month, 2 promotional broadcasts to 5,000 subscribers. Customer-initiated sessions: 3,000, most of them inside the free allowance. Bot-initiated: 10,000 sessions for the broadcasts. The broadcasts are the whole bill; the support traffic is nearly free. If the shop replaces one of the broadcasts with a segment of 1,000 recently active customers, the bill drops by almost half with little loss in orders.
Clinic, 800 conversations a month, appointment reminders to every booked patient. Customer-initiated: 800 sessions, free. Bot-initiated: one reminder per appointment, say 1,200 sessions. Small bill, and each reminder that prevents a no-show pays for hundreds of sessions.
Delivery service, 15,000 status notifications a month, 4,000 customer questions. Bot-initiated: 15,000 sessions for notifications. Customer-initiated: 4,000, part of them above the allowance. Here the trick is to send one notification per order, not one per status change, and to answer “where is my parcel” inside the session the notification already opened, which costs nothing extra.
How to keep the bill down
- Reply inside open sessions. If the customer wrote in the last 24 hours, your answer is free; do not wait until tomorrow.
- Bundle notifications. One message with the full status instead of three messages an hour apart.
- Segment broadcasts. Recent buyers convert several times better than the whole base; the session cost is the same per recipient.
- Let the bot and the AI operator answer first. Every question resolved without an operator saves operator time, which is usually the bigger cost.
- Watch the counter weekly. The session counter shows both kinds of sessions; a broadcast that went to the wrong segment is visible the same day.
Viber bot vs Viber Business Messages
They are different products with different pricing. A bot is a two-way chat: customers write to it, it answers, it can notify subscribers by sessions. Business Messages are one-way transactional and promotional messages to any phone number, without a prior conversation, billed per delivered message. Many companies use both: Business Messages for order confirmations to new customers, the bot for everything after that. The Viber Business Messages page covers the second product.
Summary
Registration and building cost nothing; Viber bills 24-hour sessions, free when the customer starts them and paid when the bot does; the platform is a monthly plan with optional AI and verification. For a real quote pick your countries on the session pricing page or ask the team through the contact form with your expected volumes.