What Is OSOS?

In short: OSOS (the Turkish acronym for automatic meter reading system) is the system through which the electricity distribution company reads your meter remotely via a modem. Subscribers whose annual consumption exceeds the limit set by EPDK are brought into scope. You see your data on the distribution company's OSOS portal with a username and password obtained by application.

What Is OSOS?

OSOS is the automatic transfer of the index and load profile data stored in electricity meters to the distribution company's central system through a communication unit (modem). No one visits the site to read the meter; the billing indexes and the consumption curve within the period are collected remotely.

The distribution company owns and operates OSOS. The system was built primarily for accurate billing, loss tracking and grid planning; subscribers get read-only access to the data through a portal.

How Does OSOS Work?

• Electronic meter: Records active and reactive indexes (including the T1/T2/T3 time bands) and the periodic load profile.
• Communication unit (modem): Connects to the meter via RS-485 or the optical port and sends the data to the centre over a GSM line or another communication infrastructure used by the distribution company. In some meters the modem is integrated.
• Central system and portal: The distribution company validates the data, passes it to billing and publishes it on the OSOS portal the subscriber can view.

Who Is in OSOS Scope? (Limits and 2026 Status)

The obligation to be included in OSOS depends on annual active electricity consumption. The limit is set by EPDK Board decision and differs by distribution region; the last general change was made by the EPDK decision dated 21.04.2016. The lowest limit is 10 MWh per year, applied in the Dicle Electricity Distribution region. Meters whose consumption exceeds the limit must be brought into OSOS within one year at the latest.

Under the smart meter transition rules, meters of consumers with annual consumption above 10 MWh are to be replaced, starting with the highest consumers, with Smart Meter PRO units or OSOS-compatible meters and modems; the target date for at least 40% of these meters per distribution company was set as 1 January 2026.

Subscribers below the limit can also be included in OSOS at their own request or their supplier's request.

How Do You Get an OSOS Password? (Portal Application)

To access the OSOS portal, the subscriber applies to its distribution company. The process differs slightly between companies, but the general steps are the same:

1. Download the OSOS password request form from the distribution company's website.
2. Fill in the form with subscription and authorised person details; attach the documents the form asks for (such as a signature authority document for corporate subscribers).
3. Submit the application to the incoming documents office or send it to the distribution company's KEP (registered electronic mail) address.
4. Once the application is approved, the username and password are sent to you.

If you forget your password, use the portal's “Forgot Password” option or apply to the distribution company again.

OSOS Portal Addresses

The addresses below are the OSOS portals of the respective distribution companies. For regions not listed, check the OSOS page on your distribution company's website.

Who Pays for the OSOS Modem?

Electricity meters are owned by the distribution company; for meters in mandatory scope, providing the meter and an integrated modem is the responsibility of the party that owns the meter. If a meter is included in OSOS at the subscriber's or supplier's own request, the requesting party provides the communication unit and hands it over to the distribution company, which installs it free of charge. All physical work on the meter and modem is carried out by the distribution company's crews.

What Is OSOS Data Good For, and What Are Its Limits?

The OSOS portal lets you see indexes, the load profile and billing-period consumption. It is valuable for checking the bill, reviewing contracted capacity and following your reactive ratio during the period.

Its limits are equally clear: OSOS shows only the distribution company's main meter; there is no breakdown by panel, transformer or device. Data is usually published with a delay, it does not alarm you when a limit is exceeded, and it does not combine the data of different buildings on one screen.

OSOS vs an Industrial EMS

The two systems are not competitors. OSOS is the official billing data; an EMS lets you see the consumption behind that bill at its source and act on it. Argus EMS can show main meter data from the distributor portals it has access to side by side with its own field readings, so bill reconciliation and sub-meter breakdown sit on the same screen.

Frequently Asked Questions

Related guides: what is the reactive energy penalty?, the reactive penalty calculator and what is an energy analyser?