How to Put a Challenge Wait on Xiaomi: The Complete Guide

Mobile has long since ceased to be just a means of conversation, becoming a complex communication tool where skipping a call can cost an important transaction or personal agreement. Xiaomi smartphone owners working on the shell of MIUI or the new HyperOS often face a situation where a second call is received during a conversation and the device simply resets it or gives busy beeps, instead of offering to put the subscriber on hold. This is because by default the waiting function can be disabled at the level of the SIM card or the device itself, and it requires intervention in the system settings to activate it.

Call Waiting allows you to avoid missing incoming calls while you are busy talking to another person, switching between lines or pausing the current speaker. On Chinese brand devices, activation of this option is sometimes hidden in the depths of the engineering menu or requires the input of special devices. USSD-It's a code, because the standard settings interface may not display the switch because of the region's firmware. GSM/VoLTE, This will help you avoid situations where your phone is unpredictable.

In this article, we will discuss in detail all the known ways of activating a service, from simple actions in the phone menu to working with engineering codes that are usually hidden from the eyes of the average user. You will learn why different SIM cards (MTS, Beeline, Megaphone, Tele2) the behavior of a smartphone can differ, and how to force the option to be turned on if standard methods do not work. We will also touch on the topic of voice waiting, which is often confused with conventional line retention, and explain the difference between these concepts.

Activation through the standard Android settings menu

The easiest and safest way to enable the feature is to use the built-in interface of the Android operating system, which on Xiaomi smartphones is adapted to the MIUI shell. This method does not require knowledge of special codes and is suitable for most users whose SIM cards fully support modern communication standards. However, it is worth considering that the location of the elements may vary slightly depending on the firmware version and regional settings of the device.

To start, open the standard Phone app, which usually has a green phone icon, and go to the settings menu. In newer versions of the shell, this menu is called by clicking on three dots in the upper right corner or via the “More” button, then select “Settings” or “Additional Settings.” Here you are interested in the section related to accounts and networks, which is often called “Accounts and Syncs” or simply “Network and Internet”, but in the context of calls, you need to look for the “Calls” subsection.

Inside the call menu, you'll see a list of active SIM cards, if there are two, and a set of options for each. Find Additional settings and click on it. The system will try to request the current status of services from your mobile operator, which can take a few seconds. In the list that opens, look for the "Waiting for a Call" option and activate the slider next to it. If the switch is active, then the service is connected and working correctly.

⚠️ Warning: If after switching on the slider it spontaneously returns to the “Off” position after a few seconds, this is a signal that the service is not activated on the side of your mobile operator or there are failures in the current network coverage area.

Sometimes the interface may require re-authorization on the network, so once the function is enabled, it is recommended to restart the device.This will allow the smartphone to re-register on the network with updated service parameters. Also make sure that you have data transmission or stable signal enabled, since the request for service status requires the exchange of data packets with the base station.

Use of the USSD-service-management codes

In cases where the GUI does not allow you to change the settings, or if you prefer quick commands, come to the rescue. USSD-These codes are sent directly to the mobile operator's server, bypassing the complex menus of the smartphone, and allow you to instantly activate, deactivate or check the status of the call waiting service.

The standard code *43# is used to manage the call waiting service, which is universal for GSM networks. By dialing this combination in the dialing field and pressing the call button, you will receive an instant response from the network about the current status of the function. If the service is turned on, a confirmation message will come, if it is turned off, the network will prompt it to activate or simply report the current state. The forced activation often uses the same code, but sometimes requires confirmation via a return call or SMS.

In addition, there are deactivation codes (#43#) and status check codes (*#43#) that can be useful in diagnosing problems. If the standard code doesn't work, it could mean that your operator uses its own short numbers to manage services, in which case you need to refer to the operator's help or use a special application "My operator", where this feature is often duplicated in a user-friendly interface.

• 📞 *43# – activation of call waiting service.
• ❌ #43# - Complete shutdown of the function.
• ❓ *#43# – Checking the current status of the service.
• 🔄 *#43# – Repeated status request (if the first one fails).

If you are in an area where only 4G/LTE catches without voice calls (VoLTE is not configured), the request may not pass. In such situations, try temporarily switching the network type in the 3G or 2G settings, execute a command, and then return it all back.

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If the *43# code doesn’t work, try dialing it by adding a grille symbol at the end, such as *43*1#, as some operators use modified versions of the standard codes to activate services.

Customization through the Xiaomi Engineering Menu

For advanced users who don’t find the right option in the standard menu, there is access to a hidden engineering menu (Engineering Mode), which is designed to test the hardware and software components of the phone by developers, but also contains useful features for managing network parameters, including fine-tuning voice calls.

To get to the menu, open the Phone app and dial the combination ##4636##. If the code is entered correctly, the screen automatically switches to the Testing menu, where you do not need to press the call button. In the list that opens, select Phone information. There is a lot of technical data here, but we are interested in the lower part of the screen where the network function switches are located.

In the list of options, find the option associated with waiting for a call. It can be called "Turn off radio" (do not touch!), "Ping test" or have a name containing the word "Call." Look specifically for the Call Waiting item or similar in meaning. If there is no such item explicitly, perhaps your version of the firmware blocks access to these settings through this menu, and then you will have to use alter-native methods such as dealer applications or operator codes.

⚠️ Warning: Be extremely careful in the engineering menu. Changing the settings you are not sure about (for example, the preferred type of network or the settings of the radio module) can lead to loss of communication, disappearance of the device. IMEI or unstable phone operation.

After making changes to the engineering menu, be sure to restart the device. The system should apply new network configurations at start. If the function does not work after the reboot, try resetting the network settings to factory ones, but remember that this will remove the stored Wi-Fi and Bluetooth pairing passwords.

Voice expectation and its difference from the usual

Often users confuse the call waiting function with the operator's Voice Mail or Answering Machine service. These are fundamentally different things: if the former allows you to see and switch to an incoming call, the latter simply records a message from the caller when you can't or don't want to answer.

Voice waiting on Xiaomi is not set up in the phone menu, but through operator commands. For example, to forward to voice mail when a line is busy, a certain code is used, which each operator has a different one. The smartphone in this case only redirects the call to the operator's server without participating in the process of recording a message. Activating this feature is useful if you are often busy and do not want to miss calls at all, but physically can not speak right now.

Call forwarding is usually required to activate voicemail. The standard code for setting a call forwarding "if busy" is **67* voicemail number #. The voicemail number can be found from the operator or in its application. Once the command is entered and confirmed, the network will report the successful activation.

The difference between these technologies is critical to understanding how your phone will behave in a stressful situation, and if you want to pause and switch, you need to wait for a call. If you want people to respond to an answering machine, you need Voicemail.

Solving problems with displaying the waiting option

There are times when the “Waiting for a Call” item on the menu is simply missing or gray (inactive).This is a common problem on Xiaomi smartphones with two SIM cards, when the settings apply only to one of them, and for the second interface is not updated, and the cause can also be a software conflict, especially if you recently upgraded from MIUI 13 to 14 or HyperOS.

The first step in diagnosis is to check which SIM card you are trying to turn on the feature for. The call settings menu always has a choice. SIM-Make sure you pick the right one. If the option is grey, try pulling out the SIM card, wipe the contacts and paste back in, then reboot the phone. Sometimes the physical contact is disrupted and the phone can't read the SIM card service class.

If the problem is software, resetting the Phone app can help. Go to Settings → Apps → All apps, find Phone (or Calls), click Clear and select Clear All Data. Don't be afraid, contacts and call history will not be lost, only the settings of the call app itself are reset.

• 🔄 Restart your smartphone in Safe Mode to eliminate the impact of third-party apps.
• 📱 Check for system updates in the About Phone menu».
• 📞 Call the operator support team to check the service on the network side.
• 🗑️ Remove and add the SIM card again in the mobile network settings.

In some cases, changing your phone’s settings helps. Go to Settings → Advanced Settings → Region and selecting a country other than yours (such as India or the US) can unlock hidden menu features, as different regions have different telecommunication law requirements.

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If nothing helps, the problem may be the problem. SIM-map: old SIMKS (released more) 5-7 years ago) may not support modern service management protocols and need to be replaced in the cabin.

Features of working on two SIM cards

Owners of two-sym Xiaomi devices often face the nuances of waiting for a call working on only one SIM, which is related to the architecture of the modem and how the operating system allocates the resources of the RF path. When one SIM card is busy talking, the second one can go into unavailability mode or simply do not register incoming if the correct redirect is not configured.

To work properly on two numbers, you need to configure the function independently for each SIM card. Go to the call settings, select the first SIM card, turn on the wait, then go back, select the second and repeat the procedure. It is important to understand that during a conversation on the first SIM card, the second one may not be available for incoming ones if the "Redirect When not available" function is not enabled.

Modern smartphones with support for DSDS (Dual SIM Dual Standby) allow you to keep both SIMs waiting, but at the time of a conversation, one of them can lose the 4G network and fall into 2G/3G. This is normal behavior for most devices that do not support dual standby technology in 4G networks. Turning on VoLTE on both numbers greatly improves the situation, allowing you to stay on the 4G network during a conversation.

⚠️ Attention: When actively talking on the first SIM card, an incoming call to the second SIM card may not appear on the screen, but immediately go to voice mail or be reset if the forwarding “unavailable” to the first number is not configured.

For business users who are critically important not to miss calls to any of the numbers, it is recommended to use the application “Mi Drop” or analogues to synchronize calls between devices, or configure a redirect from the second number to the first during important conversations.