The liberalization of the electricity market began in 1995, and, as of September 2006, all consumers (domestic and non-domestic) have the right to choose their electricity supplier.

In 2011, termination process of regulated end user tariffs for electricity began, and transitional end user tariffs started to apply. This termination process had the following schedule:

  • January 2011: Very High Voltage (VHV), High Voltage (HV), Medium Voltage (MV) and Special Low Voltage (SLV) consumers
  • July 2012: Normal Low Voltage (NLV) consumers with a contracted power greater than or equal to 10.35 kVA
  • January 2013: Normal Low Voltage (NLV) consumers with a contracted power of less than 10.35 kVA

Suppliers of last resort (SLR) started applying the transitional end user tariffs to electricity consumers who were still being supplied on a regulated market basis and had not chosen a new supplier. These tariffs are expected to exist until the transitional period ends, on 31 December 2025(Administrative Rule No 83/2020, of 1 April).

On 1st January 2018, the scheme  equivalent to transitional tariffs was established, according to which any NLV customer may choose an electricity supply contract with prices matching the regulated market, through their supplier or, if the supplier does not offer a contract with these characteristics, by switching to the SLR.

Economically vulnerable customers maintain access to the regulated end customer tariff and to applicable social discounts.



Retail market

As part of the activity of following up and monitoring the retail electricity market, ERSE collects information on electricity prices (Order No 18637/2010, of 15 December), namely:

  • Prices of commercial offers (reference prices), made available by the various suppliers
  • Invoiced prices, which are sent to ERSE every quarter by all suppliers in the electricity market (free suppliers and regulated suppliers)

The prices of commercial offers are disclosed by ERSE through the Commercial Offers Newsletters and the energy price simulator, which help consumers choose their supplier.

ERSE publishes the Liberalised Market Newsletter, which includes various matters, namely those relating to the evolution of the liberalised market, market shares, the intensity of supplier switching, the structure of switching or market concentration.

ERSE publishes an annual report  with an analysis of the electricity and natural gas retail markets in Portugal, including detailed information from an annual perspective and considering the medium and long term evolution.