CHALLENGE

Keeping up with growing parcel volumes with minimal customer visibility

Hrvatska Pošta Mostar is one of three public postal operators in Bosnia and Herzegovina, a structure unique in the world. Covering a smaller territory than the other two operators, the company runs Brza Pošta alongside BH Pošta and Pošte Srpske, a joint express delivery service operating nationwide since 2016. As eCommerce accelerated parcel volumes, traditional letter volumes fell, and customer expectations grew.

The company needed to modernize how it communicated with customers receiving packages, and it needed to do it fast.

As a public entity, Hrvatska Pošta Mostar operates under procurement protocols that require predicting message volumes months in advance, difficult when parcel demand fluctuates seasonally and grows unpredictably. The institutional complexity was real, but so was the urgency.

• No proactive communication. Customers had no advance notice a parcel was coming. They waited, guessed, or called in.
• No delivery flexibility. Packages went to the registered address only. A missed delivery meant a failed attempt, a return trip for the driver, and a frustrated customer.
• A call center under pressure. Agents handled a constant stream of short, repetitive calls – parcel status checks, opening hours, delivery windows. Each call was brief. Collectively, they consumed significant capacity.
• No self-service path. Customers could call or visit the website. There was no middle ground.

Building a proprietary app was considered and rejected. Getting customers to download something new was the wrong battle. Therefore, they needed a partner to provide communication channels people already use.

SOLUTION

Turning delivery notifications into a two-way delivery experience with Viber

Rather than building a proprietary app and hoping customers would download it, Hrvatska Pošta Mostar partnered with Infobip to implement Viber as a key communication channel for customer engagement. Viber’s penetration across the market made it the right foundation to build on, and they needed that reach. We helped them build the communication layer gradually, adding functionality as their internal systems could support it.

Hrvatska Pošta Mostar uses Viber Business Messages for two main use cases:

• Delivery notifications: A simple one-way message: your parcel has been received and will be delivered today. For the first time, customers knew a delivery was coming before it arrived.
• Management messages: Notifications became interactive, with a link letting customers redirect their parcel to a parcel locker available 24/7, or to any post office branch in their delivery territory, including cash-on-delivery parcels. The flow takes under a minute: the customer receives the Viber message, taps the link, and selects a pickup point. For delivery teams, more redirected parcels mean fewer wasted trips to empty addresses and fewer repeat attempts on the same route.

When a Viber message fails to deliver, SMS serves as an automatic failover channel, ensuring no notification goes undelivered.

Alongside Viber messaging, Hrvatska Pošta Mostar is using a Viber chatbot through our chatbot building platform. Customers can opt in through tapping a direct link or scanning a QR code on their website that opens the conversation in Viber instantly, or by searching for the Brza Pošta 123 account directly inside the Viber app.

The conversation opens with a branded welcome screen and a structured menu of four options; no free typing required, no waiting on hold. Customers tap their way to an answer in under a minute:

• Send a parcel. Customers who want to ship can enter their details, calculate a price based on parcel weight and delivery timeframe, or request a contract directly through the bot. The request routes automatically to the customer service team, who dispatch a courier to the address provided. For small businesses and eCommerce sellers managing their own web stores, this has become a go-to: a fast, repeatable way to book collections without picking up the phone each time.
• Track a parcel. Customers enter a tracking number and get instant status. No phone call, no website navigation, no waiting.
• I have a question. A direct route to customer service information, including opening hours, contact details, holiday schedule changes, and a service rating option. Exactly the short, repetitive queries that previously kept call center agents tied up.
• Find us. Customers can locate the nearest branch, follow Hrvatska Pošta Mostar on social media, or access general terms and conditions, all without leaving the conversation.

Across notifications, management messages, and the chatbot, customer communication that once relied on phone calls and in-person visits has shifted to a digital, self-service model.

RESULTS

Higher engagement with fewer 
failed deliveries  

In 2025, Hrvatska Pošta Mostar sent more than 500,000 Viber management messages, averaging around 41,700 messages per month. In the first five months of 2026 alone, more than 300,000 customer interactions were recorded, increasing the monthly run rate to over 60,000 interactions.

This represents a 44% year‑over‑year increase in customer interactions on Viber, reflecting growing adoption of proactive delivery communication rather than a comparison across channels.

Daily interactions also increased from approximately 1,400 in 2025 to over 2,000 in 2026, meaning thousands of customers now actively use Viber every day to track parcels, receive delivery updates, and manage their deliveries in real time.   

Rather than serving as a pure comparison to previous channels, these volumes show how widely customers have adopted proactive delivery notifications and self‑service delivery management through Viber. Thousands of customers interact with these messages every day to stay informed and make delivery decisions before an attempt is made.

For customers, the difference is clear. Those who once had no visibility over their deliveries now receive real-time notifications before a driver leaves the depot. The rigid, address-only delivery model is largely gone. Every day, more than 2,000 customers actively manage their deliveries, redirecting parcels to a time and location that suits them, all in under a minute. Failed deliveries are down, and drivers cover routes with fewer wasted stops and fewer repeat attempts at empty addresses.

The Viber bot took the pressure off the call center in a way that compounds over time. Routine queries that once kept agents on the phone, parcel status checks, opening hours, and holiday schedules are now handled automatically, around the clock. Agents are freed for conversations that actually need a human.

The clearest proof of impact came when a technical issue took the system offline. Call volumes surged immediately, as customers phoned in asking why they could no longer track parcels, manage deliveries, or use the Viber chatbot to get answers on their own. What began as a modernization initiative had become a critical part of the delivery experience.

Looking ahead, the next phase is already in motion: more parcel locker locations, AI-driven automation, and deeper integration across channels. Hrvatska Pošta Mostar and Infobip continue to build on more flexible, efficient, and customer‑centric delivery operations.