NOS SGPS

Capital/Financing Update • Oct 1, 2025

NOS, SGPS, S.A. Registered Office: Rua Ator António Silva 9 – Campo Grande 1600-404 Lisbon Registered in the Commercial Registry Office of Lisbon and Corporation no. 504 453 513 Share Capital: 257,580,690.00 Euros

ANNOUNCEMENT

Fitch Ratings affirms NOS at "BBB" issuer credit rating

Lisbon, 1 October 2025 - Pursuant to the terms and for the purposes of article 29-Q(3) of the Portuguese Securities Code and article 17 of Regulation (EU) No 596/2014 of the European Parliament and Council of 16 April 2014, 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 reflects its "established market positions and robust financial performance". The rating agency also notes its expectation that NOS will "continue to improve cash-flow generation before dividends," and will maintain a comfortable level of indebtedness, below the reference of around 2x Net Financial Debt/EBITDA AL as defined in its financial policy.

This confirmation by Fitch of the investment-grade long-term issuer default rating reaffirms NOS's access to financing sources under competitive terms.

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

Lisbon, 1 October 2025

Contacts Pedro Cota Dias Head of Investor Relations & Corporate Finance Email: ir@nos.pt Tel.: +351 21 782 4725