O2 Mobile Unlimited: Flat-rate 5G plan for heavy data users

With O2 Mobile Unlimited, Telefónica S.A. targets heavy data users in Germany who want flat-rate 5G mobile service and do not want to track gigabytes or worry about overages.

Responsible: ad hoc news B2B & Pro Desk. Reviewed prior to publication on June 15, 2026 at 10:40:43 AM ET. Details in the imprint.

O2 Mobile Unlimited is Telefónica S.A.'s flat-rate 5G mobile tariff line for customers in Germany who want unlimited data, calls, and texts without watching a monthly data cap. The plan family is designed for heavy data users, remote workers, and small businesses that rely on mobile connectivity all day and prefer predictable monthly costs. Rather than a fixed data allowance, subscribers get flat-rate mobile data on the O2 network in Germany, including access to 5G where available for compatible devices. For users who spend a lot of time streaming, video conferencing, or tethering a laptop on the go, the proposition is straightforward: use the network normally without worrying about gigabytes.

What O2 Mobile Unlimited offers heavy data users

According to Telefónica's O2 brand, O2 Mobile Unlimited is built around a simple promise: unlimited surfing, calling, and texting in a single postpaid contract on the German O2 network. Instead of a traditional bucket that might throttle speeds or trigger overage fees after a threshold, the tariff is marketed as flat-rate mobile data under standard usage conditions. For many power users, that aligns with how they already use smartphones and mobile hotspots: as primary internet access for cloud apps, messaging, and entertainment, particularly in households or small offices that rely on mobile rather than fixed broadband.

From a feature standpoint, O2 Mobile Unlimited typically bundles unlimited domestic calls and texts within Germany alongside the unlimited data component. That means customers do not have to track voice minutes or SMS either, which can simplify billing and expense planning for freelancers or small-business owners who submit phone costs. Where 5G coverage is available on the O2 Germany network, compatible smartphones and routers can tap into higher peak speeds and lower latency, which helps when running bandwidth-hungry apps or hosting video meetings from mobile connections.

O2 positions these Unlimited plans within its broader O2 Mobile portfolio as an option for particularly intensive usage scenarios. While the company also markets tiered data plans, the Unlimited line is pitched at customers who would otherwise bump into those limits regularly. That includes people who stream HD or 4K video on the go, gamers who value low-latency connections, and professionals who frequently tether laptops or tablets while traveling between client sites. The predictable billing profile can also appeal to small businesses that want to avoid surprises on monthly invoices.

Exact monthly prices for O2 Mobile Unlimited vary by specific tariff variant, contract length, and ongoing promotions, and are quoted in euros for the German market. Telefónica directs customers to the O2 online tariff overview for up-to-date pricing details and any time-limited offers. Prospective subscribers can compare Unlimited options against other O2 Mobile plans to decide whether paying a premium for flat-rate data makes sense relative to their historical usage. Because pricing promotions change over time, shoppers who are sensitive to cost will want to check the current offers on the O2 website before signing a contract.

Ordering O2 Mobile Unlimited is possible through multiple channels. Customers can sign up via the official O2 online portal, over the phone, or in O2 branded shops across Germany. In addition, authorized retail partners that sell O2 contracts can offer O2 Mobile Unlimited alongside other tariffs. For newly signed plans, customers typically receive a SIM card and, where applicable, can pair the tariff with a new smartphone or router financed over the contract period, depending on the specific offer and credit approval policies published by O2.

From a network perspective, O2 Mobile Unlimited runs on Telefónica's O2 network infrastructure in Germany, which the company has been expanding with 5G coverage and additional capacity. Heavy data users who consider such a plan often look at coverage maps and independent network tests to see how well the O2 network performs in their region. While those external measurements can change year by year, Telefónica highlights its ongoing 5G rollout and modernization efforts in Germany in corporate statements aimed at both consumers and investors. For many professional users, consistent coverage at home, at the office, and along daily travel routes matters as much as theoretical peak speeds.

For international usage, O2 typically outlines roaming conditions separately from domestic flat-rate features on its tariff pages. Business travelers and frequent vacationers in other European countries will want to check O2's published roaming policies, data fair-use thresholds within the EU, and any additional fees that might apply outside standard roaming zones. These details can affect the total value proposition for Unlimited plans if a significant portion of usage occurs while traveling abroad rather than within Germany.

From the standpoint of Telefónica S.A., O2 Mobile Unlimited fits into a broader strategy of emphasizing high-value, data-centric contracts that encourage customers to stick with the brand long term. Heavy data users tend to be relatively low-churn subscribers when service quality matches expectations, which can support recurring revenue stability. Shares of Telefónica S.A. (ES0178430E18, ticker TEF) last traded on the New York Stock Exchange at a closing price reported for June 12, 2026, according to official market data.

O2 Mobile Unlimited at a glance

• Product: O2 Mobile Unlimited
• Manufacturer: Telefónica S.A.
• Category: B2B/Pro line mobile tariff
• Launch date: Ongoing tariff line within the O2 Mobile portfolio in Germany
• MSRP / Price: Monthly euro pricing varies by Unlimited variant and current promotions; official tariff details are listed on the O2 Germany website
• Availability: Available via the O2 online portal, O2 branded shops in Germany, and authorized O2 sales partners
• Target audience: Heavy mobile data users, remote workers, and small businesses seeking predictable mobile connectivity costs
• Key feature / USP: Flat-rate mobile data with 5G network access on the O2 Germany network, reducing the need to monitor monthly data volumes

This article was created with a.i. assistance and editorially reviewed. Product information is provided without warranty; prices and availability may change at any time. Not investment advice, not a buy or sell recommendation. Trading in securities carries risks up to the total loss of capital.