Billing321

AI-native billing for utilities. The AI runs locally, your data stays with you — synchronized in real time, logged without gaps. Built on more than a decade of experience in the utilities sector.

Billing321
under the hood

Modular structure — one data flow

Each application is its own codebase with its own database. The event bus (Apache Kafka) connects them: the operator bills in the core, the customer sees the result in the portal immediately — real-time synchronization, with no application depending on the availability of another.

Billing core

Calculations, tariffs, accounts, meters, meter readings, tasks, contracts, people. This is where all the business logic lives.

Billing core: the operator's workspace

Customer portal

What the end customer sees: balance, billing and payment history, meter readings, chat. Data arrives automatically from the core.

Customer portal: the subscriber's view
everything at a glance

Account card

The complete picture of a subscriber — balance, meters, residents, transactions, tasks, change log. All on one page.

Balance card: calculated, paid, due
Meter readings
Residents log
Billing periods
Transactions
Tasks
Change log
Balance card: calculated, paid, due

Balance card: calculated, paid, due

Meter readings

Meter readings

Residents log

Residents log

Billing periods

Billing periods

Transactions

Transactions

Tasks

Tasks

Change log

Change log

AI assistant

AI built in from day one — and AI is also used to develop the modules themselves. The operator asks a question in natural language — and gets an answer computed from the real data.

Not tied to a single AI provider. Several are connected — from large cloud services to local models that run without internet. On-premise capable: data does not leave the company perimeter.

Internal chat
Claude

@ai What is the current balance of account 1001 and when was the last payment?

10:36 AM

AI Assistant AI

The current balance of account 1001 is €109.76 (credit), the last payment was on 10 Jan 2026 for €50. [via Claude]

10:37 AM

Message…
from the customer's side

Mirrored interface

The billing core and the customer portal are mirror applications. Operator and customer see the same data through an identical interface. Synchronized over Kafka, in real time.

The subscriber sees the same data as the operator — synchronized over Kafka.

Created on

15 Apr 2026, 09:37

Created by

Demo, Admin

Balance €109.76
Calculated
€309.76
Paid
€200.00
Due
€109.76
Current charges as of 16 Apr 2026
€7.77

Last payment: 10 Jan 2026

Last meter reading: 20 Feb 2026 (89 m³)

Calculation: 16 Apr 2026, 10:31 (billing.calculate)

Refresh all Payment
Meters Add

CW

CW-1001 · Installed: 16 Apr 2026

Reading

HW

HW-1002 · Installed: 16 Apr 2026

Reading

Real-time communication

Built-in chat in real time, bound to a specific account. Customer messages are mirrored into the billing core automatically — full transparency.

The customer communicates with the operator — access limited to their own account.

CW

CW-1001 · Installed: 16 Apr 2026

Reading

HW

HW-1002 · Installed: 16 Apr 2026

Reading

Hello, how can I submit my meter readings online?

10:31 AM

Staff

Thank you for your enquiry! The information has been forwarded to the responsible department.

10:31 AM

Message…
Residents log
Meter readings
Transactions
Billing periods

Why Billing321

AI-native

AI is part of the architecture, not an add-on — built into the modules and used to build them.

On-premise capable

Local AI models (Ollama), data does not leave the company.

Security architecture

Billing core without internet access, portal via DMZ, separate databases.

Open

Modular architecture, event-driven (Kafka), no vendor lock-in on AI providers.

Automated checks

End-to-end check scenarios across all modules — automatic, with screenshots and a report. Results can be verified, not just taken on trust.

All screenshots on this page were generated automatically by these scenarios.