How to get an Android device's serial number, visible to the user in "Settings > About phone/tablet/device > Status > Serial number".

README.md

NOTE 2021/01/08: As of Android 10 (API level 29), there's no way for non-system and non-carrier apps to get the device's serial number, not even by calling the new Build.getSerial() method with the READ_PHONE_STATE permission, since per the docs it'll always either return Build.UNKNOWN (API < 29) or throw a SecurityException (API >= 29). This means that the code below might not work on some devices running Android 10+, due to changes in the Android OS itself and AFAIK there's no work around. See this official guide to migrate from using the device's serial number ; the Settings.Secure.ANDROID_ID might also be a good replacement. Also read the comments to see how other people are dealing with this problem, maybe someone has found a solution that will help you.

Devices tested

This code snippet has been successfully tested on the following devices and Android versions :

• Archos 133 Oxygen : 6.0.1
• Google Nexus 5 : 6.0.1
• Hannspree HANNSPAD 13.3" TITAN 2 (HSG1351) : 5.1.1
• Honor 5C (NEM-L51) : 7.0
• Honor 5X (KIW-L21) : 6.0.1
• Honor 9 Lite (LLD-L31) : 8.0
• Huawei M2 (M2-801w) : 5.1.1
• Samsung Galaxy S5 (SM-G900F) : 6.0.1
• Samsung Galaxy S6 (SM-G920F) : 7.0
• Samsung Galaxy Tab 4 (SM-T530) : 5.0.2
• Xiaomi Mi 8 (M1803E1A) : 8.1.0

Device.java

import android.os.Build;

import java.lang.reflect.Method;

public class Device {
    /**
     * @return The device's serial number, visible to the user in {@code Settings > About phone/tablet/device > Status
     * > Serial number}, or {@code null} if the serial number couldn't be found
     */
    public static String getSerialNumber() {
        String serialNumber;

        try {
            Class<?> c = Class.forName("android.os.SystemProperties");
            Method get = c.getMethod("get", String.class);

            // (?) Lenovo Tab (https://stackoverflow.com/a/34819027/1276306)
            serialNumber = (String) get.invoke(c, "gsm.sn1");

            if (serialNumber.equals(""))
                // Samsung Galaxy S5 (SM-G900F) : 6.0.1
                // Samsung Galaxy S6 (SM-G920F) : 7.0
                // Samsung Galaxy Tab 4 (SM-T530) : 5.0.2
                // (?) Samsung Galaxy Tab 2 (https://gist.github.com/jgold6/f46b1c049a1ee94fdb52)
                serialNumber = (String) get.invoke(c, "ril.serialnumber");

            if (serialNumber.equals(""))
                // Archos 133 Oxygen : 6.0.1
                // Google Nexus 5 : 6.0.1
                // Hannspree HANNSPAD 13.3" TITAN 2 (HSG1351) : 5.1.1
                // Honor 5C (NEM-L51) : 7.0
                // Honor 5X (KIW-L21) : 6.0.1
                // Huawei M2 (M2-801w) : 5.1.1
                // (?) HTC Nexus One : 2.3.4 (https://gist.github.com/tetsu-koba/992373)
                serialNumber = (String) get.invoke(c, "ro.serialno");

            if (serialNumber.equals(""))
                // (?) Samsung Galaxy Tab 3 (https://stackoverflow.com/a/27274950/1276306)
                serialNumber = (String) get.invoke(c, "sys.serialnumber");

            if (serialNumber.equals(""))
                // Archos 133 Oxygen : 6.0.1
                // Hannspree HANNSPAD 13.3" TITAN 2 (HSG1351) : 5.1.1
                // Honor 9 Lite (LLD-L31) : 8.0
                // Xiaomi Mi 8 (M1803E1A) : 8.1.0
                serialNumber = Build.SERIAL;

            // If none of the methods above worked
            if (serialNumber.equals(Build.UNKNOWN))
                serialNumber = null;
        } catch (Exception e) {
            e.printStackTrace();
            serialNumber = null;
        }

        return serialNumber;
    }
}

@ammdsoftdev
Testing on Xiaomi Redmi 9C (Android 10). always returns unknown.
Does this have resolution for android 10?

As written in the readme it's not possible anymore to get the device's serial number on devices running Android 10 or newer. AFAIK there's no workaround since it's a limitation enforced by the Android OS itself.