Decimal Digit Character: \d
Imports System.Text.RegularExpressions Module Example Public Sub Main() Dim pattern As String = "^(\(*\d{3}\)*[\s-])*\d{3}-\d{4}$" Dim inputs() As String = { "111 111-1111", "222-2222", "222 333-444", _ "212-111-1111", "01 999-9999" } For Each input As String In inputs If Regex.IsMatch(input, pattern) Then Console.WriteLine(input + ": matched") Else Console.WriteLine(input + ": match failed") End If Next End Sub End Module