Investments

Our networks and our technology together form the core of our value creation. That is why we are systematically building out and interlinking our fixed and mobile networks because our strategic goal is to offer our customers the fastest possible connection at top quality, anytime, anyplace. And we remain committed to investing extensively going forward. At our 2024 Capital Markets Day, we announced plans to reinvest around 21 % of our service revenues through 2027 (Deutsche Telekom excluding T‑Mobile US and before spectrum investment). Group-wide, in 2025, we invested EUR 16.9 billion (not including spectrum investment) primarily in building and operating networks, with EUR 5.9 billion of this figure spent in Germany alone. This makes us the biggest single investor among all of our German competitors. In pursuit of outstanding quality and an even quicker and more efficient network build-out, we are also striking out in new directions, for example, with the use of artificial intelligence to ensure infrastructure is built out in line with demand. Integrated network management improves the capacity utilization of our infrastructure and increases efficiency in operations and maintenance.

Fiber optic-based fixed networks are the basis for integrated network experiences. The build-out of our fixed-network infrastructure with future-proof optical fiber is our priority. In Germany, we made fiber-optic lines (FTTH) available to 2.5 million further households and companies in 2025 through our own build-out efforts and through partnerships. A total of 12.6 million households and businesses in Germany now have the option to subscribe to a fiber-optic line with us. In 2026, we want to maintain the same high build-out pace and give a similar number of new households access to fiber. By 2030, every household and every business in Germany is to have access to a fiber-optic line. Our aspiration is for Telekom Deutschland to build the majority of these. The German broadband market is characterized by slow, declining growth and sustained intense competition, mainly from alternative network operators. There is a clear uptick in the number of customers using optical fiber. At the same time, there is a shift from DSL to FTTH. More than 580 thousand new customers subscribed to a fiber-optic line from us in 2025, an increase of approximately 25 % compared with the prior year. Contract terminations, mainly for DSL lines, are offsetting this positive trend, and led to us losing around 50 thousand broadband customers in the reporting year. To return to growth in the broadband market by winning even more customers for our fiber-optic network in the future, we adjusted our fiber strategy in the reporting year. Going forward, we will focus more on building out fiber to entire buildings, particularly multi-dwelling units in urban areas, alongside ramping up our sales activities and building out to rural regions.

Alongside our own build-out efforts, we also rely on partnerships with around 50 partners Germany-wide past and present (including public utility companies in the cities of Münster, Kassel, and Regensburg), with around half based on the fiber platform model. Under this model, the local partners build out fiber on the ground, while Telekom Deutschland leases the passive infrastructure and ensures open, non-discriminatory network operation. In the reporting year, we agreed our biggest partnership yet: working with Munich’s public utility companies and M-net to deliver fiber to 550 thousand households. Another form of cooperation we use is joint ventures. In this model, Deutsche Telekom establishes a jointly owned network build-out venture with a partner. This venture operates independently and serves to accelerate the fiber build-out through its activities. In the past, we have founded two joint ventures. Since 2020, Glasfaser NordWest – a joint venture with EWE – has been building the network of the future in Germany’s northwest. In addition, in 2022 we established GlasfaserPlus together with the Australian private equity firm IFM. GlasfaserPlus operates nationwide and focuses in particular on expanding fiber infrastructure in rural areas.

In the Europe operating segment, the number of broadband customers grew by 3.1 % against year-end 2024 to 7.4 million. A total of 11.3 million households (coverage of 43.1 %) in the footprint of our European national companies have access to our high-performance fiber-optic network.

In the United States, too, we are set to add fixed broadband to our service portfolio. T‑Mobile US is leveraging its leading position in respect of mid-band mobile spectrum to offer customers fixed wireless broadband access via FWA. At the same time, T-Mobile US aims to give between 12 and 15 million U.S. households access to fiber by the end of 2030. To this end, T‑Mobile US took steps in the reporting year to significantly improve its position with the successful acquisitions of Lumos and Metronet. T‑Mobile US also has plans for further collaborations. In the reporting year, for the first time ever T‑Mobile US launched its own lineup of fiber plans in the shape of “T‑Mobile Fiber Home Internet”.

The positive response shows that our efforts are paying off. We received further awards in 2025: Deutsche Telekom made an impression in the nationwide network test of internet providers in Germany with reliability, contractual compliance, and the lowest latency. With an overall score of 1.62, we were named test winner in the network test conducted by the trade magazine Chip. We also once again performed well in the 2025 Connect readers’ choice awards in Germany and were voted #1 in the categories “Fixed-Line-Provider” and “IPTV services.” Connect trade magazine rated us the best nationwide provider in Germany (09/2025 issue) and Austria in its fixed-network test. Our Austrian network was recognized for the fifth time as the fastest fixed-network internet in the 2025 Ookla® Speedtest Award. It was also named test winner with the top score of “very good” in the fixed-network internet test conducted by Imtest.

In mobile communications, we set ourselves apart from our competitors with the quality of our network that has been singled out for awards in several network tests. With 5G, we are creating a highly reliable mobile network with extremely low latency and high data throughput. In August 2025, we had already met our goal of giving around 99 % of the German population access to 5G by the end of 2025. 5G standalone with network slicing and other innovative functions is available to our consumers via dedicated rate plans. Together with Nvidia, we brought a brand-new 5G+ gaming offering to the market in the reporting year. Network slicing and intelligent network optimization enable us to deliver highly stable response times for mobile cloud gaming directly on smartphones. Deutsche Telekom’s business customers have already had access to this technology for some time now, e.g., for live TV broadcasts or in 5G campus networks for industry and research. We utilize AI technology as a tool to help us continually evolve our networks: With the introduction of the RAN Guardian Agent in 2025, we are the first network operator to deploy a sophisticated AI agent in network management. The agent is capable of analyzing network behavior, identifying performance anomalies, and autonomously initiating corrective actions. It supports network management teams and significantly cuts down response times when troubleshooting is required in the network. The RAN Guardian Agent is our first step towards autonomous, self-healing networks.

As of the end of 2025, our national companies covered on average 91.9 % of the population in our European footprint with 5G.

We consistently top the independent network tests: In the 2025 Connect readers’ choice awards in Germany, Deutsche Telekom once again was rated best in the categories “Mobile Network Operator” and “Prepaid Cards from Network Operators”. We also again won the three big mobile network tests by the trade magazines Chip, Connect, and Computer Bild – the first and only network on test ever to receive a score of “excellent” in the Chip test. In the Imtest network test of German mobile providers, Deutsche Telekom was rated best overall with a score of “very good.” Ookla awarded our national companies in Poland and Greece the prize for the fastest mobile network. For the eleventh consecutive time, the mobile network of Cosmote Telekom in Greece received the Best in Test Award from Umlaut for speed and quality. Hrvatski Telekom once again has the best mobile network in Croatia according to independent testing by the Croatian regulatory authority. Independent network tests rated T‑Mobile US’ mobile network the best in the United States: Ookla confirmed the U.S. subsidiary’s continued 5G network leadership in terms of speed and performance.

Our strategic goal is to be able to use the best-in-class integrated network infrastructure for our products and services. That is why we are complementing our own infrastructure with that of strategic partners, while also considering alternative access networks (e.g., satellites). In the reporting year, T‑Mobile US and SpaceX launched their joint T-Satellite offering in the United States, delivering basic telecommunications services with low data volumes to areas where terrestrial mobile coverage cannot reach. Satellite-based communication now also supplements classic terrestrial IoT networks (NB-IoT, LTE-M, 4G, and 5G). In the reporting year, we expanded our set of partners for IoT plans with satellite connectivity. Deutsche Telekom IoT can now serve even more use cases with even greater geographical reach through existing roaming partner Skylo and our new partners Sateliot and OQ Technology.

The delivery of connectivity and services based on our own and our partners’ infrastructure is reliant on technology- and domain-agnostic orchestration capabilities. These are found in a separate technical control layer above the actual infrastructure, which allows us to manage the “network of networks.” We are modernizing our NT/IT architecture to ensure the necessary orchestration capabilities are in place. Our focus is on leveraging the full potential of network automation, cloudification, and disaggregation to make our production considerably faster, more flexible, and more cost-efficient. Disaggregation, or the separation of hardware and software, makes it possible to add new suppliers. We made further progress in respect of the Open Radio Access Network (Open RAN) in the reporting year. One big change is that components from different technology suppliers are now interoperable using open, standardized interfaces. Over a thousand such Open RAN sites are already transmitting in Telekom Deutschland’s mobile network. We are planning for more than 3 thousand Open RAN-compatible cell sites by the end of 2027.