T Mobile US : ESG Materiality Assessment and Stakeholder Engagement Brief

ESG Materiality Assessment and

Stakeholder Engagement Brief

Topic Summary

A critical step in developing a strategic approach to corporate responsibility and external reporting is effectively identifying, assessing, and prioritizing environmental, social, and governance (ESG) risks, opportunities, and impacts. An ESG materiality assessment is

a widely used tool for defining the significance and relevance of specific ESG topics for businesses, accounting for their industry, regulatory environment, and key stakeholders. A materiality assessment plays a crucial role in enabling companies to identify the most important ESG topics that impact business value and stakeholders.

Stakeholder engagement is a key piece of the materiality assessment process and how we continue to evolve our corporate responsibility strategy and communicate on our progress. We engage with internal and external stakeholder groups on a regular basis throughout the year and we do specific outreach as part of our ESG materiality assessment work in order to understand the topics that are most important to them and our business.

T-Mobile's Strategic Approach to ESG Materiality

As part of our broader work to regularly assess our ESG priorities, we conduct an updated ESG materiality assessment every few years. These assessments help us stay on top of emerging trends, get insights into stakeholder expectations, and identify what has the greatest potential to impact our business and where we can have the greatest impact on society and the environment.

Aligning with leading practices and new reporting guidelines, we engaged an independent third party to conduct a double materiality assessment in 2023, which identified 20 key ESG topics for our business. This process evaluates the identified ESG topics to understand how significantly they may positively or negatively impact T-Mobile's enterprise value (financial materiality) and society and the environment (impact materiality). In both cases, potential impacts are considered over both short- and long-term time horizons.

The assessment was informed by the definitions of materiality from the Global Reporting Initiative (GRI) and Sustainability Accounting Standards Board (SASB). It also aligns with the double materiality process outlined by the Corporate Sustainability Reporting Directive (CSRD). The results of the assessment guide our disclosure strategy and are integrated into T-Mobile's ESG approach and broader business strategy.

ESG Double Materiality Assessment Process

We followed a four-step process to guide the identification and prioritization of the most significant ESG topics impacting our business and our stakeholders.

DOUBLE MATERIALITY

The double materiality process assesses topics based on financial materiality and impact materiality across short- and long-term time horizons across the entire value chain.

Impact Materiality

Impact materiality evaluates the

potential impact we can have on society,

the economy, and the environment.

Financial Materiality

Financial materiality evaluates the potential impact of a topic on enterprise value.

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OUR ASSESSMENT PROCESS

Identify list of topics, informed by:

1. T-Mobilescorporate priorities, business strategy, and enterprise risk management
2. Existing ESG reporting and prior materiality assessments
3. Leading sustainability frameworks and standards

1. ESG-relatedregulations
2. Industry trends and benchmarking
3. Brand perception survey
4. On-goingstakeholder feedback

Understand internal and external stakeholder perspectives through:

1. In-depthinterviews with T-Mobile executives from across the business
2. In-depthinterviews with external stakeholders representing civil society organizations, industry and sustainability organizations, suppliers, and investors

1. Employee survey responses
2. Customer survey responses
3. Desktop research to supplement stakeholder perspectives and understand potential impacts over different time horizons

Synthesize and score the topics:

1. Topics were assessed using the following criteria:
   i. The likelihood and potential frequency of impacts, risks, and opportunities and where along our value chain they might occur
   ii. The severity of impacts, risks, and opportunities on enterprise value considering items such as business strategy, reputation, and compliance
   iii. The likelihood and potential frequency that the company's actions can have an impact on society and the environment through that topic
   iv. The severity of impacts, risks, and opportunities on society and the environment, including scale, scope, and ability to be remediated

1. Each topic was then scored from low to high using the following two measures to determine their thresholds (moderate, high, and very high priority):
   i. Level of impact on the business (likelihood x severity)
   ii. Level of impact on society and the environment (likelihood x severity)

Validate findings:

1. Shared results with internal participants interviewed for this assessment
2. Validated findings with our ESG Steering Committee and the Nominating and Corporate Governance Committee of the Board

1. Integration into ESG approach
2. Align with ESG reporting efforts

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ESG MATERIALITY ASSESSMENT RESULTS

The results of the assessment identified 20 topics, grouped into four categories based on their level of impact on our business operations as well as their implications for society and the environment.1

• Category 1: Focus on priority topics
  Includes topics that ranked the highest priority because they have a higher impact on society, the environment, and/or on enterprise value as current business drivers or topics associated with higher risks and opportunities. Many topics in the first category are viewed as very important in the near-term and ranked as having medium to high importance on longer time horizons.

• Category 2: Sustain and grow strategic programming
  Includes topics that ranked as high priority and represents a range of important topics that T-Mobile is expected to continue to responsibly manage or grow strategic programming around. Some of these topics have greater potential for impact over longer time horizons, while others are topics the company has already made ambitious commitments on and therefore should continue to sustain ongoing efforts.

• Category 3: Manage foundational table stakes
  Includes topics that ranked at the moderate threshold and includes foundational operational integrity topics, such as ethical business practices and executive and board oversight and accountability, that are an integral part of our business that stakeholders expect us to continue to manage to reduce business risks and result in sound corporate governance.

• Category 4: Monitor moderate topics and emerging trends
  Includes topics that do not currently represent high risk or high impact, but are still important to manage and monitor, such as product lifecycle management and waste, as well as emerging trends such as natural resources and biodiversity.

E ENVIRONMENTAL	S SOCIAL	G GOVERNANCE
 Climate Risk and Resilience	 Diversity, Equity, and Inclusion	 Business Continuity and
 Energy Use	 Emerging Technology and	Network Resilience
 Natural Resources and Biodiversity	Product Innovation	 Cybersecurity
 Product Lifecycle Management	 Employee Attraction, Development,	 Data Protection and Privacy
and Engagement
 Waste and Recycling	 Sustainable and Responsible
 Community Engagement and	Supply Chain
	Philanthropy	 Ethical Business Practices
	 Digital Equity	 Executive and Board Oversight
	 Employee Health, Wellness,	and Accountability
	and Safety
	 Public Policy, Partnerships,
	and Collaboration
	 Responsible Use of Products
	and Services
	 Responsible Marketing

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1 Topics are listed in alphabetical order within each category.

ESG MATERIALITY ASSESSMENT AND

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ESG Material Topics Definitions and Insights

Topic	Definition	Key Insights

Business	Developing and implementing risk mitigation, business
Continuity and	continuity, and community support strategies to prepare
Network	for and respond to a wide range of potential natural and
Resilience	human caused disruptions and to reduce the potential of
	equipment or software failures from disrupting service.
	Investing in network enhancements that promote
	reliability, coverage, and speed.

Our large and wide-ranging customer base coupled with the increasingly frequent occurrence of significant natural and human caused disasters underscore the importance of network resilience and emergency preparedness efforts to promote reliable connectivity and reduce potential disruptions for business and society.

Climate Risk Taking clear action to prepare for and manage the

and Resilience negative impacts and risks to the company and customers presented by climate change; reducing the climate impact of the company's operations; adopting adaptation and mitigation strategies across T-Mobile's value chain to manage transition risks; and developing innovative technologies and services that promote long-term sustainability.

Addressing climate change risks is necessary to adapt to changing weather patterns and continue to improve network resilience and connectivity in the face of increasingly severe weather events.

Taking action to reduce emissions and improve impacts on the climate through our operations, products, and services can promote efficiency, innovation, and business resilience while helping to meet the expectations of stakeholders.

Community	Engaging with communities to enhance their well-being	As a brand with customers, employees and facilities
Engagement	and livelihoods year-round and supporting them in	across the country, it is a priority to invest in these
and	times of need through disaster relief efforts; promoting	communities and engage with them in impactful ways.
Philanthropy	employee action to give back and have a positive impact	Our philanthropic and employee volunteering programs
	in their communities.	allow us to uplift causes that are important to our people
		and communities. They also enable us to empower
		our employees to meaningfully give back, which is an
		important contributor to employee morale and being
		a good corporate citizen.
		Investments in restoring and maintaining connectivity for
		communities in the immediate aftermath of disasters or
		disruptions are a key vehicle for community engagement
		and maintaining a strong, trusted brand reputation.
		Navigating these moments well can have a positive
		impact on communities and first responders relying
		on connectivity, which is increasingly important as
		the potential frequency and severity of weather events
		and other disruptions grow.
Cybersecurity	Building a network and environment to facilitate a safe	Continued monitoring and investment in cybersecurity
	and secure online experience for customers and reducing	innovations is vital to effectively thwart new techniques
	cyber-related risks through policies, systems, and	and modes of attacks from bad actors. Effective
	security controls.	management mitigates risk and builds trust among
		existing and prospective customers.
Data Protection	Protecting and responsibly managing consumer and	To maintain a reputation as a trusted brand, it is essential
and Privacy	employee personal data; respecting individuals' rights	to handle customer and employee data with utmost care.
	of privacy in the collection, storage, use, and transfer	This involves collecting, storing, using, and sharing such
	of personal data; providing customers with resources	data with informed consent, while ensuring the protection
	to empower them around their online safety.	of personal and/or sensitive information.
Digital Equity	Promote broadband affordability, availability, and	Digital connectivity is increasingly important to the
	adoption through products, services, and network	personal, economic, and social vitality of people and
	coverage; supporting digital skills-building and literacy	communities. Expanding equitable and affordable access
	programs to create a more digitally inclusive society.	and investing in digital skills yields positive impacts
		on communities and society, allowing people to take
		advantage of more digital services and products.

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ESG Material Topics Definitions and Insights continued

Topic	Definition	Key Insights
Diversity,	Promoting diversity of the company's workforce at	Inclusivity and equity in the workplace can lead to greater
Equity, and	all levels, fostering an inclusive workplace culture,	innovation for our customers, improve the morale and
Inclusion	and supporting equal opportunity for employees	career development of employees, and enable greater
	of different backgrounds.	customer attraction and retention in diverse markets.
Emerging	Promoting responsible innovation or deployment of	Responsible innovation of emerging technologies can
Technology	new or emerging technologies and digital products and	enhance our product and services offerings as well as
and Product	services (such as artificial intelligence or Internet of	lead to more efficient business operations. The ability
Innovation	Things) while promoting the respect of human rights.	to evolve and deploy new technologies in safe and
		responsible ways to directly address customer pain points
		is increasingly important for competitive advantage,
		particularly in the fast-paced technology industry.
Employee	Attracting, retaining, and developing the best talent	Investing in learning and career development programs,
Attraction,	through education, training, fair recruitment, and	creating a welcoming environment, and providing
Development,	compensation practices; creating an inclusive and	resources and benefits to support employees are all key
and	engaging culture; and respecting employees' rights	to attracting talent and fostering employee satisfaction
Engagement	to freedom of association.	and retention.
Employee	Providing safe working conditions for employees where	Health and well-being have a direct impact on employee
Health,	exposure to potential health and safety hazards are	satisfaction and productivity. In addition to prioritizing the
Wellness,	minimized and their mental well-being is prioritized;	physical safety of employees, particularly those in retail,
and Safety	promoting programs that emphasize health and wellness.	there is also a growing recognition of the importance
		of employees' mental health. Providing safe working
		conditions and supporting the well-being of employees
		helps attract and retain top talent.

Ethical Business Applying fair, transparent, and ethical business standards

Practices that govern the strategic and operational management of the business including the actions of its representatives, and relationships with business partners and third parties.

Ethical business principles and practices are critical to earning and maintaining trust with customers and employees and to maintaining our license to operate.

This requires incorporating ethical practices throughout everyday operations, establishing mechanisms for accountability, and instilling ownership in our employees. Active monitoring and assessments of adherence to those principles is necessary to identify and rectify any potential gaps.

Energy Use	Implementing energy management strategies for
	all energy consumed in the company's business
	operations and value chain to help optimize energy
	use and reduce GHG emissions.

Monitoring and managing energy use provides opportunities to increase efficiency and lower carbon emissions in our operations and across the value chain. Diversifying our energy sources not only promotes sustainability, but it also supports local economies and can better insulate us from price shocks in the energy market.

Executive	Establishing Board-level and executive structures to	Engaging the highest levels of governance on ESG
and Board	responsibly manage, oversee, and direct the company	issues is important to effectively drive strategy and
Oversight and	and integrate ESG across the business.	accountability on topics that impact the business
Accountability		and our stakeholders.
Natural	Protecting the biodiversity of our ecosystems and	It is becoming increasingly crucial to conserve natural
Resources and	preserving natural resources, such as water, trees,	resources and protect biodiversity to mitigate the
Biodiversity	wildlife, and land.	impacts of climate change and promote healthy
		ecosystems. While our operations are not generally
		natural resource intensive, infrastructure construction
		and/or maintenance (e.g. data centers or cell towers)
		may impact biodiversity and other resources.

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ESG Material Topics Definitions and Insights continued

Topic	Definition	Key Insights

Product	Promoting programs and initiatives that extend the
Lifecycle	product lifecycle and reduce the waste of the devices
Management	and products the company sells, including providing
	reuse and recycling opportunities for customers through
	take-back programs, reducing plastic and packaging,
	and responsible end-of-life management.

Effectively addressing electronic waste and packaging lowers value chain emissions from manufacturing through end-of-life and can help realize cost savings. It also enables customers to be more sustainable and more easily dispose of products and packaging.

Public Policy, Promoting and advancing environmental sustainability,

Partnerships, human rights, and social impact efforts for the company

andand across the telecom industry through advocacy,

Collaboration lobbying, participation in industry associations, external partnerships, political contributions, and cross-industry collaboration.

Current social, political, and economic developments provide opportunities for public, bilateral, and collaborative engagement and advocacy with a wide range of stakeholders and/or other industry participants on relevant issues, such as equity and inclusion, technology innovation, climate resiliency, and clean energy infrastructure.

Responsible	Providing responsible, fair, and transparent communication,	Implementing responsible marketing practices is key
Marketing	promotion and/or selling of products and services to	to protecting brand reputation and maintaining trust
	consumers.	with customers.
Responsible	Supporting the safe and responsible use of the company's	Relevant stakeholders such as investors, parents and
Use of Products	products and services by customers (including vulnerable	caregivers, and regulators are becoming more interested
and Services	groups such as children) and employees to help protect	in understanding and assessing how the technology
	their digital well-being and human rights through	industry at large is addressing this issue of responsible
	safeguards and resources that promote building healthy	use of products and services. It is therefore important
	digital habits.	to monitor and develop best practices as products or
		services are developed or expanded.

Sustainable and Building a strong, diverse, resilient, and transparent

Responsible supply chain through responsible and sustainable

Supply Chain procurement processes and ongoing supplier engagement that protect and promote the company's ESG values.

Our supply chain is a critical piece of our business and represents the majority of our carbon footprint. Establishing comprehensive policies, practices, and engagement strategies help set clear expectations about our values and spur opportunities to partner together on making positive change.

Waste and	Reducing the amount of waste generated across the
Recycling	company's operations, supporting efforts that divert
	more waste from disposal (through repair, reuse, and
	recycling), and responsibly managing all waste streams.
	This includes network equipment, IT equipment, and
	waste from facilities, among other things.

As a company with a large retail, network, and corporate footprint across the country, it is important to collaborate with employees and local waste management groups to responsibly and sustainably manage the reuse, recycling, and disposal of waste and e-waste generated across the business. Reducing waste and reusing materials can promote cost savings and reduce negative impacts

on the environment.

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T-Mobile's Strategic Approach to Stakeholder Engagement

Stakeholder relationships are critical to how we continue to evolve our ESG approach. Ongoing dialogue and engagement with our stakeholders are fundamental to advancing our work and driving progress where it matters most. Their input helps us align our actions with the priorities most relevant for our industry and business to make meaningful and purposeful change.

STAKEHOLDER GROUP	ENGAGEMENT CHANNELS
Customers	• Customer surveys
We changed the wireless industry	• Market research
by listening to and responding to our
customers - understanding what
matters most to them is critical to
solving their pain points.

• Interactions with our retail and customer care employees
• Email, T-Mobile Tuesdays, and social media

Employees

Our people are at the heart of the Un-carrier. Getting their feedback on their experience and the issues that impact them is a priority for us.

• Employee surveys
• Employee Resource Groups (ERGs)

• Employee volunteering programs
• Emails, newsletters, internal T-Nation site, internal collaboration tools

		Communities	•	Philanthropic partnerships	•	Industry and community
		Local officials, community partners,	•	Community events	•	memberships
		advocacy organizations, and industry	•	Volunteering events and job fairs	One-on-one conversations
		associations help keep us informed	•	Industry association meetings	•	External Diversity and Inclusion
		about what's important to the people
					Council meetings
		and communities we interact with.
		Industry analysts	• One-on-one conversations	• Major industry conferences
		We regularly engage with industry		and email exchanges	• Industry analyst reports
		analysts who provide valuable feedback	• Industry Analyst Council	• Analyst Days
		on our strategy, industry trends, and

opportunities to further enhance our ESG reporting.

Investors

Frequent and transparent communication with investors provides us with opportunities to understand their ESG priorities and communicate our progress and commitments.

• One-on-one conversations	•	Major industry conferences
•	and email exchanges	•	Capital Market Days
Group meetings
•	Quarterly earnings calls

Suppliers

Ongoing engagement is foundation to developing long-lasting, mutually- beneficial relationships with suppliers who share our values and commitment to operating in a responsible manner.

• One-on-one conversations	• Supplier questionnaires
•	and email exchanges	•	Educational discussions around
Vendor onboarding forms		key ESG topics
•	Supplier risk and ESG	•	Program partnership conversations
	assessments

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Commitment

We commit to conducting impact-based materiality assessments every 2-3 years to reflect current trends, financial impacts on the company, as well as impacts on society and the environment.

Governance

Our executive-led ESG Steering Committee oversees, elevates, and provides strategic direction for ESG programs, initiatives, as well as reporting and disclosure efforts. This includes validating the ESG materiality findings and using the results to inform our ESG and disclosure strategies.

The Nominating and Corporate Governance Committee of the Board provides oversight for T-Mobile's corporate responsibility efforts and receives quarterly briefing on key ESG topics, emerging trends, and progress. This includes updates on our materiality assessments.

Relevant Resources

ESG Reporting Hub

References to "materiality" in the context of such discussions and any related assessment of ESG "materiality" may differ from the definition of "materiality" under the federal securities laws or other regimes for regulatory reporting purposes. Moreover, given the uncertainties, estimates, and assumptions required to make some of the disclosures in this report, and the timelines involved, materiality is inherently difficult to assess far in advance. Certain statements we make are also informed by hypothetical scenarios or projections which rely on a range of possible factors that may not occur or may differ significantly from actual events, and as such should not necessarily be viewed as being representative of current or actual risk or forecasts of expected risks.

© 2024 T-Mobile USA, Inc.

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