UScellular and T-Mobile are coming together to deliver a better wireless experience for our customers, and many improvements are already available today:

• Stronger network performance: The networks have been integrated, bringing broader coverage, more reliable calling, and faster data speeds. Customers are gaining expanded access to T-Mobile’s nationwide 5G network.

We’re currently focused on integrating networks to give you the best experience possible. In the coming months, early integration with T-Mobile’s 5G network will support:

• More on-network calls for improved reliability
• Faster speeds to help your team stay productive on the go
• Expanded coverage that reaches even more places your business operates in

Once UScellular accounts fully migrate to T-Mobile systems, you’ll unlock the full strength of T-Mobile’s nationwide network—with the largest 5G network, the most towers, and a signal that reaches farther.

Plus, with the recent addition of T-Satellite, customers can take advantage of the T-Mobile satellite-to-mobile network ready to help keep your business connected in places no cell tower can reach.

As we've been diligently working on the migration to the award-winning T-Monile network, we hope you are enjoying the many improvements already in place. We're excited, because we know your experience will only get better in the months ahead.

As we continue bringing the T-Mobile advantages to more customers, some account updates must now be completed under the T-Mobile brand. Your service stays the same today.

Also, as we continue to prepare to bring the T-Mobile network experience to more customers, some additional account updates will occur. Some account activities—such as suspensions, upgrades, adding lines, plan changes, and accessory purchases—will no longer be supported on UScellular self-serve portals beginning May 1, 2026

Protecting our customers’ information is a top priority, which is why we ask for customers’ 6-digit Account Personal Identification Number ( Account PIN) to authenticate and access your account with T-Mobile Customer Support. You should have received an email from us when your account moved over that included a link to set up your Account Hub online account. If you cannot locate that email or the link has expired, you can also use the 4-digit Account PIN of the Primary Contact on your USCC account and add two 0’s to the end to make an equivalent T-Mobile Account PIN. For example, if your USCC Account PIN was 1234, your T-Mobile Account PIN will be 123400. This will allow you to set up your Account Hub account as well as access your account with T-Mobile Customer Support.

As we enter the next phase of migration, you may notice a few operational updates designed to deliver simplicity and performance. As systems align, you may see updates to plans, products, or support experiences—communicated clearly and implemented with minimal disruption. As part of this transition, we don’t expect your monthly cost to increase or a reduction in your plan benefits

Some account activities—such as suspensions, upgrades, adding lines, plan changes, and accessory purchases—will no longer be supported on UScellular self-serve portals starting May 1, 2026.

Any new Business Internet service is offered through T-Mobile.

Accounts will move in phases, over time. We’ll notify you when your account is ready to move and guide you through next steps.

There’s nothing you need to do right now.

Nothing will change right now. Your T-Mobile and UScellular accounts will continue to be managed separately.

You won’t see any changes to your current plan, pricing or benefits because of this move.

If you choose to combine or make changes to your accounts in the future once your account has moved to T-Mobile systems, we’ll guide you through your options when the time is right.

There’s nothing you need to do at this time.

No. Your phone number will not change as part of this transition.

For now, your account information and login will remain the same.

We’ll provide instructions in advance if any changes are needed after your account has moved.

Most customers don’t need to take any action.

We’ll guide you through any changes when your account is ready to move.

You don’t need to do anything right now.

Once your UScellular account has moved to T-Mobile’s system, you’ll automatically gain access to additional T-Mobile services and benefits. We’ll notify you when that happens and provide clear next steps, if needed.

While you don’t need to take action now, you can choose to migrate early. Your UScellular account expert can walk you through the details.

Early migration is similar to changing providers today—but with all the benefits of T-Mobile for Business support, rated #1 by J.D. Power Customer Satisfaction with Medium Business Wireless Service.

Whether you make the move now or wait, we’re excited for you to experience everything T-Mobile offers.

Until migration, your account tools, and invoices remain the same. After migration, you’ll enjoy:

• A new T-Mobile for Business digital portal for account management
• Direct billing from T-Mobile
• Access to T-Mobile’s full portfolio of business solutions

We’ll continue to keep you informed about every step of the way—clearly, simply, and with plenty of time to prepare.

What you can count on now:

• Your network experience will keep getting stronger.
• Our people are ready to make the transition seamless, so you can stay focused on running your business.

Yes, as a new T-Mobile customer, your account will now be subject to T-Mobile policies, which are different from UScellular policies, including differences in billing and fees for some customers.

As part of this transition, we don’t expect your monthly cost to increase or a reduction in your plan benefits

Yes, after migration, late payment fees will follow T‑Mobile’s policies and calculation methods. A late fee of $10 or a variable percentage allowed under state law is applied to an unpaid past due balance not paid by the due date.

Late payment fees are not applicable for government accounts.

Yes. A $10 payment support fee may apply when a representative assists with a one‑time payment or payment arrangement by phone or in a retail store.

T‑Mobile typically sends automatic payment requests two days before the bill due date. This timing may be different from how payments were processed previously with UScellular.

T‑Mobile may automatically attempt to retry certain failed payments when the failure is caused by correctable issues, such as missing information. This is not applicable for lines served through the IoT Platform Control Center

In many cases, yes. Most UScellular devices are compatible with T-Mobile's network. If a device or SIM card update is required, we'll notify you by email, mail, or text message. If you didn’t receive a notification, no action is required.

If a device or SIM card update is required, we'll notify you by email, mail, or text message and provide instructions. If you don't receive a notification, no action is required.

Once your UScellular account moves to T-Mobile's system, we'll share additional information and support to help ensure the best experience.

No. You can still upgrade and activate new devices, or add lines, on your UScellular account just as you always have.

However, as UScellular is now part of T-Mobile, new Internet service is offered through T-Mobile.

Your UScellular account will move to T-Mobile’s system later this year, and we’ll guide you through that process when the time comes. There’s nothing you need to do right now.

Most customers will not need to change their SIM or eSIM. Some customers may require a new SIM card.

If any updates are required, we’ll notify you ahead of time and provide clear instructions should you need to take any action.

Yes. UScellular customers can now activate T-Mobile Internet services starting at $35 per month with AutoPay, plus taxes and fees, when you have an active UScellular voice line.

Reach out to your Sales Associate for additional information.

No, T‑Mobile does not support vanity phone numbers, so this feature will be discontinued during the transition.

Lines suspended more than 200 days have been cancelled. Cancelled lines can be brought back into an active status but cannot be re-suspended.

Suspended lines that have met or exceeded the maximum temporary suspension timeline (30, 60, 90, 120 days etc.) but have not been suspended for more than 200 days have been resumed.

Beginning March 1, 2026 customers have been able to suspend their line(s) for a maximum of 30 days regardless of the suspension code selected. Also, customers can only suspend for one 30-day period. After May 1,2026 customers will not have the option to suspend services as their account is prepared to be moved to T-Mobile’s billing system.

Once migration occurs, T-Mobile offers voluntary suspension twice a year for a maximum period of 90 consecutive days for each suspension. During a seasonal suspension, your account must remain current. You can suspend individual lines of an account, while other lines remain active. For more information visit Account Suspension.

Other suspensions arrangements and offerings will no longer be available after migration.

To ensure a seamless migration to the T-Mobile systems, some accounts needed to be broken into separate accounts to ensure the products move to the correct T-Mobile platforms. In many cases the lines can be combined back into a single account once all lines are on the T-Mobile.

To help ensure your service continues working smoothly, there’s an update you need to complete soon. Your account was identified as having devices or SIMs which will no longer fully support the improved network experience. Taking care of this update now will help ensure everything continues working without interruption to your services.

Any offers or promotions you’re currently receiving will continue as part of your existing UScellular plan.

When your account moves to T-Mobile’s system later this year, we’ll make sure your current offers and promotions are honored.

If any changes are needed, we’ll notify you ahead of time and clearly explain your options.

There’s nothing you need to do right now.

As notified earlier this year, beginning April 2026, Small Businesses transitioned to T-Mobile’s Terms & Conditions automatically through continued service use.

Customer with 500+ employees please refer to the notification sent to your billing address with the following information

• No early termination fees – flexibility without penalties.
• Transparent pricing – simple, straightforward, and free of surprises.
• No annual service contracts – stay because you love it, not because you have to.

Your data remains protected under the UScellular Privacy Policy for now. You’ll be notified of any changes to the applicable Privacy Policy.

As your account moves to T-Mobile’s system later this year, your information will be used only as needed to support the transition and continue providing your services.

Your personal data will remain protected and handled in accordance with applicable privacy laws and company privacy policies.

Your U.S. Cellular contract was previously assigned to T-Mobile and will be amended, effective 30 days from the date of this letter, to reflect changes within U.S. Cellular’s business. Specifically, the Information Security exhibit, the applicable T-Mobile Services and Product annexes, including without limitation, the TfB Master Account Wireless Services Product Annex, the IoT Services Annex and Third-Party Solutions terms and conditions, as posted to the website currently found at the URL: https://t-mobile.com/business/terms-and-conditions, as may be updated from time-to-time, are incorporated into Your U.S. Cellular contract and apply to all Services, Products and Third-Party Solutions You purchase from T-Mobile. To the extent there is a conflict between the terms and conditions in Your U.S. Cellular contract and the T-Mobile terms and conditions, the T-Mobile terms and conditions will control. Your continued usage of, or payment for, any Service, Product or Third-Party Solution, 30 days from the date of this letter, will be deemed Your acceptance of the amendment. Any capitalized term not defined in this letter has the meaning set forth in the TfB Terms and Conditions.

Yes, refund eligibility and timelines will follow T‑Mobile policies once your account has moved to the T‑Mobile system. For more detail on return policy, visit Return Policy.

In some cases, accounts with pending refunds may be processed before migration to ensure billing accuracy.

Later this year, your account will move to T-Mobile’s systems. At that time:

• You’ll receive your invoice directly from T-Mobile.
• You might experience a change in bill cycle and fees (aligning with T-Mobile Terms and Conditions)
• You’ll keep your current mobile numbers.
• You’ll move to a T-Mobile for Business plan that’s the same—or better—than your current plan.

We’ll work closely with you to ensure the transition is smooth, seamless, and worry-free.

You can continue to use the same number you’re used to, such as 800-819-9373 to contact a UScellular representative for assistance, or dial 611 from your UScellular device.

Later this year, when your UScellular account moves to T-Mobile’s system, we’ll let you know if anything changes and provide clear instructions on how to contact support.

If you wish to reclaim a number, T‑Mobile holds previous phone numbers for 30 days. This may be different from previous UScellular policies.

No, AutoPay discounts typically do not apply when paying with a credit card.

No. You will not be charged any fees as a result of your account moving to T-Mobile.

As part of UScellular’s move to the T-Mobile network, your voicemail is transitioning to T-Mobile’s system. This provides better reliability, easier access, and improved support.

Before SIM conversion: dial your own number, *86, or long press 1.

After SIM conversion:

• Long press 1 — best option
• Dialing your own number — works, but always asks for PIN
• *86 — no longer works
• 123 — connects to your new T‑Mobile voicemail

You receive a new T‑Mobile voicemail box when your SIM is activated. You’ll set a new PIN and greeting the first time you call voicemail.

You’ll see a “Set Up” button in the Voicemail tab once you switch SIMs. Tap it to set PIN/greeting—unless you already set them by calling in. Previously saved voicemails on your device stay on your phone.

Yes. Before migration is complete, you can still reach your UScellular voicemail by:

• Calling voicemail
• Choosing Mailbox Options (4)
• Pressing 8 (connects you to your old voicemail box)

Migration happens overnight. Your UScellular voicemails and greetings will be moved into your new T‑Mobile voicemail automatically.

If you set up T‑Mobile voicemail before migration: your T‑Mobile greeting stays active; your UScellular greeting is stored as inactive.

If you did not set up voicemail before migration: your UScellular greeting becomes your active greeting, and you can choose to keep it or record a new one.

Use long press 1 as usual. All your old and new voicemails will be in one T‑Mobile inbox.

Key reminders:

• Long press 1 to check voicemail
• Complete the new voicemail setup once
• Temporary Option 8 lets you access old UScellular voicemail (until migration completes)
• Old messages and greetings migrate overnight
• Everything ends up in one place after migration

No. Your old voicemails are transferred during the overnight migration process.

Once migration completes, you’ll see your old UScellular messages alongside your new T‑Mobile messages.

On iPhone, any voicemails already downloaded to the device remain stored on your phone.