How to Set Up Call Retention on Xiaomi Redmi: The Complete Guide

Modern Xiaomi Redmi smartphones offer users a wide range of communication capabilities, but standard settings of the MIUI shell or HyperOS sometimes hide important call management functions. One of these features is call retention, which allows you to pause the interlocutor without interrupting the connection. This option is indispensable in business communication when you need to quickly clarify information from another contact or switch to an incoming important call.

Many device owners face a situation where the retention button is simply absent from the call interface or is inactive, often not due to a malfunction, but rather to the specifics of the SIM card setting or hidden system settings. Proper activation requires understanding the interaction between the phone's software and the services of your mobile operator.

In this detailed guide, we will take a look at the nuances of how Hold functions on Xiaomi smartphones, how to activate the service through the engineering menu, standard settings, and what to do if the operator blocks this feature, and carefully following the instructions will help you regain full control of incoming and outgoing connections.

The principle of the Hold function in mobile networks

Call retention is not just a software option in the phone, but a network service provided by a carrier. When you place a hold call, your Xiaomi smartphone sends a special signal request to the operator's network. If the service is active on the provider's side, the connection is not broken, but put into standby mode with the playback of beeps or music for the waiting subscriber.

It is important to understand that the standard GSM/UMTS/LTE This option is provided by default, but it often requires manual activation through the USSD-On Redmi devices, the system component Phone is responsible for processing these signals, which can work in conjunction with Google Dialer or a branded caller. MIUI.

There are several scenarios for using retention: you can pause the first call to answer the second incoming call, or initiate a new outgoing call while the first person is waiting. Without activated Call Waiting, the retention function will not work, since the network will simply reset second attempts to connect.

⚠️ Note: Call retention function can be paid or free depending on your operator's tariff plan. Before activating, check the charging conditions in your personal account or support service.

Technically, the process is as follows: the phone sends an activation code, the network confirms the status and starts broadcasting a waiting signal, and if at that point you try to do something that is not supported by the network, the connection can be forcibly severed.

Activation of the service through the settings of the Xiaomi smartphone

The first step to set up call retention on Xiaomi Redmi is to check the basic parameters in the device menu. The MIUI shell provides access to network services management through the standard settings interface. However, the location of these items may vary depending on the version of Android and the type of caller used.

To start, open the Phone app and go to the settings menu, usually indicated by three dots or a gear. Find Settings → Accounts and Sync → Calls (the path may vary). Here you will see a list of additional services such as forwarding, numbering, and call waiting.

If you use the standard Google Dialer, which is often preinstalled on global versions of Redmi, the path will be a little different. Click on the three dots in the top right corner, select Settings → Calls → Additional settings. In this menu, you need to find the "Waiting for a Call" item and activate the switch.

Once the switch is turned on, the phone will send a request to the network, the status will change to "On" only after confirmation from the operator. If you see an error message or status "Unknown", this means that the direct request from the phone did not pass. USSD-team.

Importantly, on two-symbol Redmi, you need to check the settings for each card separately, and users often activate the service on the main SIM card, forgetting about the second one, and then wonder why retention does not work when calling from another number.

Use of the USSD-activation code

If the smartphone menu to activate the function is not possible, the most reliable way to remain USSD-These are text commands that are sent directly to the operator’s server, bypassing the software limitations of the Xiaomi interface, which works even on push-button phones and guarantees direct interaction with the network.

To activate call retention (which is closely related to waiting), the universal code *43# is usually used. Dial this number in the Phone app and press the call button. In a few seconds you will receive a pop-up notification or SMS from the operator about the status of the service.

• 📞 *43# – activation of call waiting service.
• 🚫 #43# - Deactivation of call waiting service.
• ❓ *#43# – Checking the current status of the service.

Once successfully activated through the code, restart the Redmi smartphone, which is necessary for the system to update the network profile and correctly display the ability to make a hold call during a call. Without a reboot, the phone may not “see” that the service is now available.

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Save activation codes in notes or take a screenshot to have quick access to them when roaming or when changing devices when the settings menu may look different.

Some operators use their own short codes to manage services, for example, one of the largest Russian operators may have a code different from the standard GSM. You can find out the exact code on the official website of your provider in the section "Service Management Teams".

⚠️ Attention: When sending USSD-Roaming requests may incur additional charges for outgoing messages or requests for information.

If you receive an error message after entering the code, it may mean a technical failure on the operator’s side or a service lock at the tariff level, in which case it is impossible to set up through the codes yourself.

Configure through the engineering menu and hidden options

For advanced users who don’t find a solution in standard settings, there is access to Xiaomi’s hidden engineering menu, which allows you to manage modem settings and network preferences at a deeper level. Be careful: changing unknown parameters can lead to unstable communication.

To enter the engineering menu, open the Phone app and dial the code ##4636##. If the code doesn’t work (which is often the case on newer versions of MIUI), you may need a special app from the Google Play store, such as Activity Launcher, to run the hidden testing process.

In the menu that opens, select Phone Information. Scroll down to Call Settings or the like, and there may be switches to force the network modes to be turned on or reset the radio module.

• 🔧 Radio Information – you can see the current status of the network registration and the type of connection here.
• 📡 Set Preferred Network Type – Network Type Selection (LTE only, GSM only, etc., which may affect the performance of voice services.
• 🔄 Refresh – button to update the signal and status of the SIM card.

In some firmware versions, you can find a direct command to reset your call settings to the factory network settings, which is useful if the operator configuration file is corrupted, but don't change the values of fields you're not 100% sure about.

It's worth remembering that the engineering menu is a diagnostic tool, and if standard methods didn't work, the problem is probably not with the software settings of the phone, but with the operator's limitations or the hardware compatibility of frequencies in your area.

Problems with activation and ways to solve them

Even with the right settings, Xiaomi Redmi users may find that the retention button does not appear during a conversation. The most common reason is the lack of support for VoLTE (Voice over LTE) from the operator or the smartphone itself on your network. In 4G networks, voice is transmitted as data, and if this channel is not configured, retention may not work.

Another common problem is application conflict: If you have installed a third-party call (like Truecaller or RecCall), it can intercept call management and block system retention functions. Try temporarily removing third-party apps and checking the standard call.

It's also worth checking if Do Not Disturb mode is on or if there are any rules to block spam calls that can aggressively filter incoming call control signals, sometimes helping a simple reset of network settings.

Settings → SIM- Maps and Mobile Networks → Select SIM → Reset settings

This operation will not delete your contacts or photos, but will return all the parameters of the connection to the mobile network to the original state, after the reset, the phone will re-register in the network and receive current service profiles from the operator.

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If the retention button does not appear, in 90% of cases the problem is solved by activating the service "Waiting for a call" through the Internet. USSD-*43# or a call for support of the operator.

Frequently Asked Questions (FAQ)