How to block unfamiliar numbers on Xiaomi Redmi 9A: 5 working methods

The Xiaomi Redmi 9A is still one of the most popular budget smartphones, but owners often face intrusive calls from scammers, spammers and collectors. Unlike the flagship models, the Redmi 9A runs on a simplified version of MIUI, where some security features are hidden deeper or require manual adjustment. This article will help you understand how to effectively weed out unwanted calls without (and with) third-party applications, and avoid the typical errors that cause locking to fail.

We tested all the methods on Redmi 9A with the latest MIUI (including MIUI 12.5 and MIUI 14 for regional firmware) and highlighted those that work consistently. We focused on hidden settings that are not written in the official instructions, but that significantly enhance protection. For example, did you know that Redmi 9A can block not only specific numbers, but also entire prefixes (for example, +375 for Belarusian spammers) or even calls from hidden numbers?

Why is the standard lock in Redmi 9A not working?

Many users complain that after adding a number to the blacklist, calls still pass, and the reason lies in three key features of the Redmi 9A:

• 📱 The stripped-down version MIUI: Xiaomi’s budget models often remove some of its security features, including advanced call filtering.
• 🔄 Conflict with SIM-Card: Operators (especially Beeline and Tele2) can intercept the lock at the network level if you have activated the service "Antispam".
• 📞 VoIP calls: Spammers often use Internet telephony (for example, via WhatsApp or specialized services) that is a standard blocker. MIUI unrecognisable.

Another common problem is resetting the blacklist after the update, which is because Redmi 9A doesn't store locked numbers in the Xiaomi cloud, but locally, so if you reset your settings or update your firmware through Fastboot, the list will clear up, and the solution is to use cloud services (discussed below).

Method 1: Standard blacklist in MIUI

The most obvious way is to add a number manually, but in Redmi 9A, this process has nuances.

1. Open the phone application (pipe icon).
2. Go to the Journal section and find the unwanted number.
3. Click on the number, then select ⋮ → Lock down.
4. Confirm the action by selecting Block (not Add to Spam is another feature!).

To manage the blacklist centrally:

1. Go to Settings → Applications → Phone → Lock numbers.
2. Here you'll see all the blocked contacts. You can add a number manually by typing it into the Add number field.

Important point: Redmi 9A has disabled hidden number locks by default (where the number is displayed as "Unknown" or "Private Number") to enable it:

1. Go to Settings. → SIM-maps and mobile networks → Call settings → Additional settings.
2. Activate the option to block anonymous calls.

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If the number still rings after blocking, check if it is stored in your contacts under another name. MIUI ignores the blacklist for contacts from the phone book!

Method 2: Blocking through MIUI security settings

Redmi 9A has a hidden Security section where you can configure advanced call filtering, which works even for numbers that didn’t make a call (for example, if you received an SMS from a spammer).

Instructions:

1. Open the Settings. → PapaSSWORD & SECURITY → Number locking (on some firmwares the path may be different: Settings) → Additionally. → Security).
2. Turn on the switch to Lock unwanted numbers.
3. Click on Lock Settings and activate the options: 📵 Block unknown numbers (all numbers that are not in the contacts). 🔍 Block numbers from spam messages (if you receive them) SMS marked "spam"). 🌐 Block international numbers (useful against foreign scams).

In Redmi 9A with MIUI 12.5 and below, the "Block Unknown Numbers" option may not be available. In this case, use a workaround: add the +* prefix to the blacklist (the asterisk acts as a stand-up sign).

Method 3: Use of the Security App

Redmi 9A preinstalled the Security app (shield icon), which can block not only calls, but also SMS. However, many users do not know that it has a cloud blacklist that syncs with the Xiaomi account.

How to set up:

1. Open the Security app.
2. Go to Blocking (or Spam Protection on some firmware)
3. Enable the call blocking option and select sources to block: 📞 Numbers from spam messages (if you receive them) SMS marked "spam"). 🌍 Numbers from Xiaomi Cloud Base (updated automatically). 📋 Manual input (to add your numbers).

Synchronization with the cloud

The advantage of this method is that Xiaomi’s cloud database contains millions of spammer numbers that are automatically blocked. However, there is a disadvantage – sometimes legitimate numbers (such as delivery services) fall into this list. To avoid false positives, periodically check the Lock Log section of the same application.

Method 4: Third-party applications for blocking

If standard methods don't work, you can install specialized applications. Redmi 9A is suitable for:

• 🛡️ Truecaller: Recognises spammers from a database with a billion numbers, minus requiring access to contacts and SMS.
• 🚫 Blacklist Plus: Allows you to block numbers by mask (for example, all numbers with a prefix) +7999).
• 📵 Call Control: Callback feature to check suspicious numbers.

Important: When installing third-party blockers, disable the standard lock in MIUI to avoid conflicts.

1. Go to Settings → Applications → Phone → Permissions.
2. Turn off the permission to Change phone settings for the standard Phone application.

⚠️ Note: Some locking apps (such as Truecaller) can intercept SMS If you use mobile banking, set up exceptions for your bank number in the app.-blocker.

Method 5: Blocking through a communications operator

If the software doesn't work, you can use the operator's services, and each provider has its own anti-spam services.

Note that carrier services block calls at the network level, so they work even when the phone is turned off.

• 🔄 Do not block VoIP calls (WhatsApp, Viber).
• 📡 They can detain important people. SMS (from banks, for example).
• 🌍 They don't work roaming.

⚠️ Attention: If you have activated anti-spam from the operator, but calls still pass, check if you have activated the call forwarding service. It can bypass the lock. To turn it off, dial ##002# and call.

What to do if the lock is not working?

If you have tried all the methods, but spammers still get, check the following points:

1. Update the firmware: Older versions of MIUI (below MIUI 12) have an unstable lock. Check the updates in Settings → About Phone → System Update.
2. Check permissions: Make sure the Phone app is allowed Calls and SMS in the permission settings.
3. Disable Dual Apps: If you use app cloning (like a second WhatsApp), it can knock the blocker off.
4. Reset network settings: Sometimes lock errors are due to incorrect mobile network settings. reset to Settings → SIM-maps and mobile networks → Resetting network settings.

If the problem persists, try an alternative launcher (like Nova Launcher). In rare cases, the standard MIUI launcher conflicts with the lock system. It's also worth checking your phone for viruses - some malware can turn off spam protection.

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On Redmi 9A, the most reliable way to block is by combining the standard MIUI blacklist + cloud sync via the Security app + operator anti-spam, which closes 90% of spam calls.

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