Users of Android smartphones are often faced with the need to enter special characters in the dialing field. This may be required to activate USSD commands, configure forwarding, or access the device’s engineering menu. The main symbol that raises questions is the hashtag or hashtag sign, which in telephony is designated as number icon.
The situation is aggravated by the fact that the interface of the standard "Phone" application may look different depending on the version of the operating system Android and the manufacturer's shell, be it MIUI, One UI or pure Pixel. In this article, we will look in detail at where to find the required symbol, how to use it correctly, and what technical limitations exist when entering special codes.
Incorrect entry of such symbols often leads to connection errors or the inability to activate the desired telecom operator service. Understanding the logic of the location of the keys on the numeric keypad will help you avoid confusion and quickly perform the necessary manipulations with the SIM card or gadget settings.
Location of the pound sign on a standard keyboard
In the vast majority of cases, the symbol you need is located right on the dialing screen. The standard phone layout, be it Google Dialer or a proprietary application from Samsung, always contains a key with a hash mark. It is traditionally located in the lower right corner of the number pad, next to the zero and asterisk.
If you do not see this symbol right away, you may have the contact spelling mode activated or an additional panel open. Click on the keyboard icon to switch to digital mode. The sign # is a mandatory element of the interface for making calls and working with service codes.
Sometimes users confuse this symbol with the call or end call button. Remember: the hash mark is used to form a command, and the green tube is used to send it. Clicking on # does not initiate a call, but only adds a character to the input line.
⚠️ Attention: On some custom firmware the layout may be changed. If the icon is not on the main dialing screen, try swiping left or clicking on the three-dot button to search for additional symbols.
Using the symbol in USSD commands and services
The number sign is a critical element when entering USSD requests. These commands allow you to manage your balance, connect services or check the remaining traffic without access to the Internet. The syntax of such commands is strictly regulated and usually looks like a sequence of asterisks, numbers and hash marks.
For example, to check the balance, many operators use a combination of the form *100#. Here the sign # acts as a final character, which tells the operator system that the command has been entered completely and is ready for processing. Without pressing this key, sending a request is often impossible.
When entering long codes, such as forwarding settings, it is important to follow the sequence. An error in one character can cause the system to display an error message or perform a completely different action. Be extremely careful when typing numbers between special characters.
It is worth noting that some modern operators are switching to automatically sending commands. In such cases, after entering the numeric part, the command can go on its own, but knowing how to dial the number icon manually is still necessary for complex service menus.
Access to the engineering menu and hidden functions
In addition to the usual service codes, the hash symbol is used to enter hidden sections of the system. The engineering menu allows you to conduct in-depth diagnostics of the device, test sensors, screen and communication modules. Access to these functions is often protected by special combinations containing several characters #.
A classic example is the code ##4636##that opens the testing menu on many devices with clean Android. Entering this sequence requires precision: missing even one hash will result in the menu not opening. This is done intentionally to protect the settings from being accidentally changed by inexperienced users.
Different manufacturers use their own unique codes. For Xiaomi it may be ##6484##, and for Sony — ##7378423##. In all these combinations, the number sign plays the role of a separator or activator of submenus.
Risks of using the engineering menu
Changing settings in the engineering menu without understanding their purpose can lead to incorrect operation of the modem, loss of the network signal, or even a complete failure of the device to turn on. Use these codes for diagnostic purposes only.
If you plan to test the equipment, make sure the battery has sufficient charge. Interrupting the testing process due to a low battery may cause a software failure that will require resetting the settings to factory settings.
Typing features on different Android shells
The visual design of the keyboard may differ significantly depending on which interface is installed on your smartphone. Users MIUI ot Xiaomi may notice that the buttons are more compact and the font of the symbols is larger. At the same time, owners of One UI from Samsung will see a more minimalistic design with spaced buttons.
On devices with a small screen or in one-handed mode, the keyboard may shrink, which increases the likelihood of an erroneous press. In such situations, it is recommended to type codes slowly, checking each entered character on the screen. A mistake in pressing an adjacent key can change the meaning of the entire command.
Some shells allow you to customize the appearance of the keyboard. You can increase the font size or change the color scheme to make the characters easier to see. This is especially true for people with low vision who find it difficult to distinguish small icons in bright sunlight.
| Manufacturer | Keyboard Feature | Location # | Code Example |
|---|---|---|---|
| Google Pixel | Clean interface | Bottom row, right | ##4636## |
| Samsung | Large buttons | Bottom row, right | #0# |
| Xiaomi | Compact layout | Bottom row, right | ##6484## |
| Huawei | Custom style EMUI | Bottom row, right | ##2846579## |
⚠️ Attention: Application interfaces are updated by developers. The arrangement of elements may change after installing a new firmware version. If you don't find a button where it used to be, carefully inspect the entire screen.
Typing a character on a physical keyboard and in third-party applications
Although physical keyboards for smartphones are rare today, some users still use cases with buttons or connect external devices via Bluetooth or OTG. In this case, the input principle changes. The number sign is usually located on the same key as number 3, and is called by a combination with the key Shift or Sym.
If you use third-party dialing applications downloaded from Google Play, the operating logic may differ from the standard one. Some apps mask special characters or require confirmation before sending a USSD request. This is done for security purposes to prevent accidental calls to paid services.
In instant messengers and social networks, the symbol # is used to create hashtags. The input mechanism here is standard: switch to the symbol panel (usually the ?123 or =\<button) and find the hash mark. Unlike a telephone, here this sign has no service value for the network, but is part of the text.
☑️ Check before entering the code
When working with text fields in a browser or notes, a symbol is entered as easily as any letter. Problems arise exclusively in specialized phone number entry fields, where the system can filter out invalid characters, although the hash mark is almost always allowed.
Input problems and their solutions
Sometimes users complain that when they click on the number icon, nothing happens, or the symbol does not appear on the screen. This may be due to the Phone app freezing. In such a situation, try clearing the application cache through the system settings or simply restarting the device.
Another common problem is that the telecom operator blocks the entry of special characters. Some tariff plans or corporate SIM cards may prohibit the execution of certain USSD commands. In this case, the character is entered, but the system returns a runtime error.
It is also worth checking if dial restriction mode is enabled. Parental controls or special security applications may prohibit calls to service numbers. Disabling this feature will restore full use of the keyboard.
If the touch screen does not respond well to touches at the bottom, try turning the phone over. In some dialer applications, the interface adapts and the buttons are moved to a more convenient area.
In rare cases, the problem lies in the display itself. If the “dead zone” of the screen is precisely in the button area #, you will have to use a third-party keyboard or voice dialing if it supports recognition of the word “hash” or “hash”.
Frequently asked questions (FAQ)
Why does nothing happen with the hash after entering the code?
You may not have pressed the call button after entering the entire combination. Most USSD codes require a final press on the green tube. Also check if you have network coverage, since commands are processed by the operator in real time.
Is it possible to save a number with a # sign to contacts?
Technically this is possible, but not recommended. The hash sign in the contact number can be interpreted by the phone as a pause or wait command, which will lead to incorrect dialing of the number when trying to call from the phone book.
What is the difference between the # sign and the asterisk *
These are two different service characters. An asterisk is often used to start a command or select a sub-item in a voice menu, while a hash usually ends a command or serves as a separator. Their functions are not interchangeable.
How to dial hash if the button on the screen does not work?
Try connecting an external USB keyboard via an OTG adapter. On a physical keyboard, the character is entered using the combination Shift + 3. This temporary solution will help you enter the necessary code until the screen is repaired.
Is it safe to enter codes with several # characters in a row?
Yes, it is safe if you use proven engineering codes for diagnostics. The phone system recognizes them as a request to open a menu, and not as a command to erase data. However, avoid entering random combinations from the Internet.