NOS SGPS

Capital/Financing Update • Aug 28, 2023

NOS, SGPS, S.A. Registered Office: Rua Ator António Silva 9 – Campo Grande 1600-404 Lisbon Share Capital: 855,167,890.80 Euros Registered in the Commercial Registry Office of Lisbon and Corporation no. 504 453 513

ANNOUNCEMENT

Fitch affirms NOS at "BBB" issuer credit rating

Lisbon, 28 August 2023 - Pursuant to the terms and for the purposes of nr. 3 of article 29°Q of the Portuguese Securities Code and article 17° of Regulation nr. 596/2014 of the European Parliament and Council, NOS, SGPS, S.A. ("NOS") hereby informs:

Fitch Ratings (Fitch) has affirmed NOS' Long Term Issuer Default Rating at "BB" with a Stable Outlook.

According to Fitch, the rating assigned to NOS considers its "solid business profile" in a "mature convergent market", also highlighted by a "comfortable leverage" in line with NOS´s target leverage ratio of around 2x net financial debt / EBITDA AL. Fitch also believes that newcomer´s entry is "unlikely to be overly disruptive".

Maintaining its investment grade long term issuer credit rating by Fitch contributes to strengthening NOS' access to financing sources under competitive terms and conditions.

This information is also available on NOS's Investor Relations website in www.nos.pt/ir.

Lisbon, 28 August 2023

Contacts Maria João Carrapato Head of Investor Relations and Sustainability Email: ir@nos.pt Tel.: +351 21 782 4725 Fax: +351 21 782 4735