Java Regular Expressions to Validate phone numbers

international phone number regex

String str=  "^\\s?((\\+[1-9]{1,4}[ \\-]*)|(\\([0-9]{2,3}\\)[ \\-]*)|([0-9]{2,4})[ \\-]*)*?[0-9]{3,4}?[ \\-]*[0-9]{3,4}?\\s?";


 if (Pattern.compile(str).matcher(" +33 - 123 456 789 ").matches()) {
        System.out.println("yes");
    } else {
        System.out.println("no");
    } 

Basically, you need to take 3 or 4 different patterns and combine them with "|":

String pattern = "\\d{10}|(?:\\d{3}-){2}\\d{4}|\\(\\d{3}\\)\\d{3}-?\\d{4}";

• \d{10} matches 1234567890
• (?:\d{3}-){2}\d{4} matches 123-456-7890
• \(\d{3}\)\d{3}-?\d{4} matches (123)456-7890 or (123)4567890

Considering these facts about phone number format:-

1. Country Code prefix starts with ‘+’ and has 1 to 3 digits
2. Last part of the number, also known as subscriber number is 4 digits in all of the numbers
3. Most of the countries have 10 digits phone number after excluding country code. A general observation is that all countries phone number falls somewhere between 8 to 11 digits after excluding country code.

String allCountryRegex = "^(\\+\\d{1,3}( )?)?((\\(\\d{1,3}\\))|\\d{1,3})[- .]?\\d{3,4}[- .]?\\d{4}$";

Let's break the regex and understand,

• ^ start of expression
• (\\+\\d{1,3}( )?)? is optional match of country code between 1 to 3 digits prefixed with '+' symbol, followed by space or no space.
• ((\\(\\d{1,3}\\))|\\d{1,3} is mandatory group of 1 to 3 digits with or without parenthesis followed by hyphen, space or no space.
• \\d{3,4}[- .]? is mandatory group of 3 or 4 digits followed by hyphen, space or no space
• \\d{4} is mandatory group of last 4 digits
• $ end of expression

This regex pattern matches most of the countries phone number format including these:-

        String Afghanistan      = "+93 30 539-0605";
        String Australia        = "+61 2 1255-3456";
        String China            = "+86 (20) 1255-3456";
        String Germany          = "+49 351 125-3456";
        String India            = "+91 9876543210";
        String Indonesia        = "+62 21 6539-0605";
        String Iran             = "+98 (515) 539-0605";
        String Italy            = "+39 06 5398-0605";
        String NewZealand       = "+64 3 539-0605";
        String Philippines      = "+63 35 539-0605";
        String Singapore        = "+65 6396 0605";
        String Thailand         = "+66 2 123 4567";
        String UK               = "+44 141 222-3344";
        String USA              = "+1 (212) 555-3456";
        String Vietnam          = "+84 35 539-0605";

Source:https://codingnconcepts.com/java/java-regex-for-phone-number/