Finvest
TIMB Telecom · Brazil · Mobile · Dividend payer · Thesis updated July 20, 2026

Postpaid power, prepaid pressure

01 Running thesis

A cleaner mobile story, with cracks

The bull case is simple. TIM is selling value instead of chasing every low-price customer. In 2025, mobile service revenue grew 5.4%, and mobile ARPU rose 4.6% to R$32.8. That shows customers are paying more, mainly in postpaid plans.

Cost control is also part of the story. TIM signed a long-term American Tower agreement that combines contracts for about 9,000 towers, around 30% of its infrastructure park, into one framework through 2034. That should help limit surprise rent increases.

The bear case starts with prepaid. Lower-income users are recharging less often, and the prepaid base fell in 2025. The digital ecosystem also looks less dependable after customer platform revenue dropped 41.2% when the C6 Bank partnership ended.

This is not a broken company, but it is not a clean growth stock either. The page view fits Finn's middle-of-the-road scores: good mobile execution, improving broadband and B2B options, but real pressure from prepaid weakness, taxes, and lease costs.

Mar 2026→The 2025 Form 20-F confirmed strong mobile execution, with mobile service revenue up 5.4% and ARPU up 4.6%. It also showed customer platform revenue down 41.2%, the C6 Bank exit, the American Tower deal through 2034, and a new 10% dividend withholding tax.
Feb 2026▲TIM bought full control of I-Systems, giving it more control over fiber broadband service and costs. Broadband also returned to revenue growth in Q4, while the V8 acquisition expanded B2B digital tools.
Nov 2025▲B2B momentum improved with the Vale smart mining partnership and more IoT traction. CADE also approved the expanded Vivo sharing agreement, lowering one regulatory risk.
Jul 2025→Postpaid momentum stayed strong, but fixed broadband M&A remained unresolved. Management also became more aggressive on tower lease costs, including possible decommissioning of expensive sites.
May 2025▼TIM paused aggressive organic broadband expansion because competition was intense. Prepaid weakness and inflation-linked lease pressure became more visible.
Apr 2025→The 2024 Form 20-F supported the value-over-volume thesis, with mobile service revenue up 6.8% and mobile ARPU up 6.2%. It also added tower-sharing legal risk after a Brazilian Supreme Court decision.
Feb 2025→TIM announced the C6 Bank settlement and monetization for R$520 million pretax, while saying Nubank's MVNO had no visible impact so far. B2B IoT contracted revenue rose above R$700 million.
Nov 2024→TIM posted another quarter of margin expansion and completed its AI customer service rollout. The update also flagged prepaid recharge weakness and new entry-level competition from Nubank's MVNO.
02 Business model

Phone bills pay the bills

TIM makes most of its money by selling mobile service in Brazil. Customers pay for postpaid, prepaid, and control plans. The company also earns from fixed fiber broadband, handset sales, and smaller digital services.

The main strategy is called more-for-more. That means TIM tries to charge more by giving customers more data, better network quality, and extra services. This works best in postpaid, where customers are usually more stable and spend more each month.

TIM is trying to add new growth legs. It bought full control of I-Systems to run more of the fiber broadband customer experience itself. It also bought V8 to add more business digital services, especially in areas like IoT, logistics, agribusiness, utilities, and mining.

The model breaks if price hikes push too many people away, especially prepaid users. It also breaks if new partnerships fail to replace C6 Bank, if fiber competition keeps prices low, or if tower and lease costs rise faster than TIM can cut other costs.

03 Product portfolio

Where TIM sells

Cash cow

Mobile postpaid and control plans

This is the strongest part of the business. Postpaid growth and higher ARPU are carrying the value-over-volume strategy.

Steady

Mobile prepaid plans

Prepaid still matters for scale, but it is under pressure. Lower-income customers have been recharging less often after price increases.

Option

TIM UltraFibra fixed broadband

Fiber broadband returned to revenue growth in Q4 2025 after a period of slower expansion. Full control of I-Systems gives TIM more room to fix service quality and costs.

Growth engine

B2B IoT and digital solutions

TIM sells connectivity and digital tools to business customers in areas like agribusiness, logistics, utilities, and mining. The Vale smart mining work and V8 acquisition add weight to this push.

Option

Customer platform partnerships

This includes offers such as Zé Delivery, PIX cashback, FS Security, Kat Investimentos, and energy initiatives. The 41.2% revenue drop in 2025 shows this area is still fragile.

Steady

Handsets and devices

TIM sells phones, tablets, mini-modems, and other equipment. Goods sold revenue fell 10.6% in 2025 as the company focused on higher-value products.

04 Business segments

Mostly mobile service

Mobile service92%modest
Fixed service5%flat
Goods sold3%declining

Mix is based on 2025 total revenue in TIM's Form 20-F. B2B IoT and customer platform revenue are not separate top-level segments in this table, so they sit inside mobile service disclosure.

05 Risk factors

What could go wrong

Prepaid keeps shrinking

Medium impact · High odds

TIM's prepaid customer base fell in 2025, while postpaid kept growing. The issue is customer behavior: some lower-income users recharge less often after price increases. If this continues, the mobile growth story becomes more dependent on postpaid pricing.

We watchPrepaid customer base growth, recharge frequency, and prepaid revenue trend.

Digital partnerships disappoint

Medium impact · Medium odds

Customer platform revenue fell 41.2% in 2025 after the C6 Bank partnership ended and EXA comparisons became harder. This shows that some non-core revenue depends on partner deals that can change quickly. TIM needs newer partnerships to prove they can replace lost revenue.

We watchCustomer platform revenue and new partnership revenue after C6 Bank.

Tower and lease costs rise again

High impact · Medium odds

Telecom networks need towers, fiber, and sites, and many leases are tied to inflation. TIM has reduced some risk with the American Tower deal through 2034, but leases are still a major cost line. Higher rental and lease costs can hurt margins if prices do not rise enough.

We watchRental costs, lease liabilities, and savings from the American Tower and IHS tower plans.

Fiber stays too competitive

Medium impact · Medium odds

Fixed broadband is a tough market in Brazil, with many regional and national competitors. TIM slowed expansion before buying full control of I-Systems. If fiber net adds or ARPU weaken again, the broadband growth option becomes less valuable.

We watchTIM UltraFibra net adds, fixed service revenue growth, and fiber ARPU.

Dividend tax cuts investor return

Medium impact · High odds

Brazil enacted Law No. 15,270 in November 2025, introducing a 10% withholding tax on dividends. That changes a long-standing tax benefit for shareholders. For income-focused investors, the after-tax cash return may be lower even if TIM keeps paying.

We watchDividend policy, interest on equity mix, and the effective cash received by shareholders.

Network-sharing execution slips

Medium impact · Low odds

TIM's sharing agreement with Vivo can help reduce network costs, and CADE approval lowered one regulatory hurdle. The work still needs clean execution, including single-grid plans and the 2G shutdown. Delays could slow cost savings.

We watchVivo sharing milestones, 2G shutdown progress, and related cost savings.
06 Quick answers

In one breath

What does TIM S.A. do?

TIM S.A. runs a telecom network in Brazil. It sells mobile plans, fixed fiber broadband, business connectivity, IoT tools, and some digital partner services.

Why is postpaid important for TIM?

Postpaid customers usually pay a monthly bill and tend to be more stable than prepaid users. TIM's 2025 growth was helped by postpaid strength and higher mobile ARPU.

What happened with C6 Bank?

TIM and C6 Bank reached a settlement in 2025 that ended their partnership. After that, customer platform revenue fell 41.2%, which raised doubts about how durable TIM's digital ecosystem revenue is.

Is TIM mainly a dividend story?

TIM does pay large distributions, including dividends and interest on equity. But the new 10% dividend withholding tax in Brazil may reduce what some shareholders receive after tax.