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What is an MMI Code and What Does it Do?
Published on: July 29, 2025
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If you've ever dialled a combination of symbols and numbers on your mobile that looks something like *123# or *199#, you’ve used an MMI code, perhaps without even realising it. At Vi, we understand how important it is for you to have seamless access to your mobile network’s features, and MMI codes are one of the easiest tools to help you execute a plethora of tasks. Here, we will be taking a look at the meaning of MMI Codes, the different types of MMI codes there are, explore some of the Vi MMI Codes, and how our network helps you stay connected seamlessly. So, let’s get started!
Understanding the Meaning of MMI Code
The meaning of MMI code lies in its full form, Man-Machine Interface code. These are special codes you can enter directly into your phone’s dialler to communicate with your mobile network provider. They’re not like typical phone numbers; instead, they trigger specific functions, like checking your balance, activating a service, or getting an idea of your data usage. Think of MMI codes as shortcuts to essential network features, accessible without needing the internet.
Each MMI number serves a specific function and is typically made up of an asterisk (*) or hash (#), followed by numbers, and ending with another hash. For example, *199# is a commonly used Vi MMI code to check balances or access customer services.
Types of MMI Codes You Should Know
Not all MMI codes serve the same function; there are different types, each designed for a specific purpose. Understanding these categories can help you use them more effectively, especially when managing mobile services with a code.
USSD Codes (Unstructured Supplementary Service Data)
Supplementary Service Codes
Manufacturer MMI Codes
SIM Control Codes
These are the most commonly used MMI numbers, especially for tasks like balance checks, plan activation, or data usage. When you dial a USSD code such as *199#, your phone communicates directly with the network and displays a response on your screen, no internet needed.
These codes are used to manage network features like call forwarding, call waiting, or call barring. These codes are especially handy if you're travelling or temporarily unavailable.
These codes are used by mobile phone manufacturers (like Samsung, Xiaomi, etc.) for internal testing and settings, such as checking battery status, hardware information, or signal strength. They're not usually related to mobile plans or network services, and they vary by device model.
These codes allow you to interact with SIM-specific functions such as unlocking a SIM card or accessing SIM toolkit services. An example is entering a PIN unlock code when your SIM is locked. While not often used daily, they can come in handy in certain situations.
Each type of code plays a unique role, and together they form a comprehensive system to help users interact with both their mobile device and their network provider. At Vi, we ensure that our list of MMI codes is easy to use, so you can make the most of your mobile experience, whether you're managing services or configuring call settings.
List of MMI Codes and What They Do
We know it can get a bit confusing with all the different codes out there, so here’s a quick list of MMI codes you might find helpful if you're a Vi user:
- Balance Check: *199#
- Do Not Disturb (DND): 1909
- Call Forwarding: *21*[phone number]#
- Call Waiting Activation: *43#
Each of these codes is designed to serve a specific purpose, saving you the hassle of searching through apps or calling customer support. With a simple Vi MMI code, you can complete a range of tasks right from your keypad.
These MMI numbers work universally across most mobile handsets and don’t require mobile data, which is what makes them so convenient. Whether you’re in a low-network area or just want quick access to a feature, this list of MMI codes can be your best friend.
Why Vi Makes It Seamless
At Vi, we believe staying connected should be effortless. Our mobile plans are designed to ensure you never miss a beat, whether you’re streaming your favourite shows, video-calling loved ones, or just browsing the web. With fast data speeds, unlimited calls, and added benefits like OTT subscription at no extra cost, Vi plans are crafted to meet every need. Whether you're a light user or someone who is always online, we’ve got options that fit just right. Paired with the simplicity of a Vi MMI code, managing your mobile account has never been easier. Here are some of our prepaid and postpaid mobile plans for you:
Prepaid:
Price |
Validity |
Benefits |
₹ 379 |
1-month |
- 2GB/Day - Truly Unlimited Calls - 100 SMS/Day - Half Day Unlimited Data (12 midnight-12 noon unlimited data) - 2GB Backup Data (Data Delights) |
₹ 539 |
56 Days |
- 4GB/Day - Truly Unlimited Calls - 100 SMS/Day - Half Day Unlimited Data (12 midnight-12 noon unlimited data) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
56 days |
- 2GB/Day - Truly Unlimited Calls - 100 SMS/Day - 60 days access to ViMTV - Half Day Unlimited Data (12 midnight-12 noon unlimited data) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
|
84 days |
- 2GB/Day - Truly Unlimited Calls - 100 SMS/Day - 3-month access to JioHotstar Mobile - Half Day Unlimited Data (12 midnight-12 noon unlimited data) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
|
₹ 1599 |
84 Days |
- 2.5 GB/Day - Truly Unlimited Calls - 100 SMS/Day - Netflix Basic Subscription (TV+Mobile) for 84 days - Half Day Unlimited Data (12 midnight-12 noon unlimited data) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
₹ 3599 |
365 Days |
- 2GB/Day - Truly Unlimited Calls - 100 SMS/Day - Half Day Unlimited Data (12 midnight-12 noon) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
₹ 3799 |
365 Days |
- 2GB/Day - Truly Unlimited Calls - 100 SMS/Day - 1 year Subscription to Amazon Prime LITE - Half Day Unlimited Data (12 midnight-12 noon) - Weekend Data Rollover - 2GB Backup Data (Data Delights) |
Subscribers using our prepaid services in Karnataka, Andhra Pradesh, Rajasthan, Madhya Pradesh, Odisha, Assam, Northeast, Jammu and Kashmir, and Himachal Pradesh circles will be able to access Unlimited Data all day, every day with our Non-Stop Superhero plans.
Postpaid:
Price |
Validity |
Benefits |
Monthly |
- 50GB with 200GB Monthly Rollover - Unlimited Night Data (12 Midnight to 6 AM) - Unlimited Calls - 3000 SMS/Month
- Vi Games: Play Esports, Multiplayer games & more for free on Vi App
- JioHotstar: 1-year mobile subscription
- EaseMyTrip: 1-year access to flat ₹750 discount per month on return flights |
|
₹551 (Vi Max 551) |
Monthly |
- 90GB with 200GB Monthly Rollover
-Unlimited Night Data (12 Midnight to 6 AM)
- Vi Games: Play Esports, Multiplayer games & more for free on Vi App
- Amazon Prime: 6-months trial with paid yearly auto-renewal
- JioHotstar: 1-year mobile subscription
- SwiggyOne: 1-year access (two coupons of SwiggyOne quarterly membership) |
₹751 (Vi Max 751) |
Monthly |
- 150GB with 200GB Monthly Rollover
-Unlimited Night Data (12 Midnight to 6 AM)
- 3000 SMS/Month |
Monthly (6-month lock-in) |
- Unlimited Data, Unlimited calls
|
Besides the aforementioned, we also have Postpaid family plans that are meant for family usage, and they start from INR 701 per month. Subscribers using our postpaid services in Karnataka, Andhra Pradesh, Telangana, Rajasthan, Madhya Pradesh, Chhattisgarh, Odisha, Assam, Northeast, Jammu and Kashmir, and Himachal Pradesh circles will be able to access Unlimited Data with the aforementioned plans.
MMI codes may seem like a small part of your mobile journey, but they carry a lot of power and convenience. At Vi, we make sure these codes are simple, accessible, and functional so that you can stay in control of your services with ease. From understanding the meaning of MMI code to exploring the list of MMI codes available to you, everything is built around your comfort and connectivity, and when combined with our high-speed network and thoughtfully designed plans, the result is a seamless mobile experience.
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