asp.net regex for phone number

Question

I am using following Validation Express for phone number on web application

ValidationExpression="^([\+]?[0-9]{1,3}[\s.-][0-9]{1,12})([\s.-]?[0-9]{1,4}?)$"

 <asp:RegularExpressionValidator ID="Phone" runat="server" ErrorMessage="*" ControlToValidate="txt_Phone" ValidationExpression="^([\+]?[0-9]{1,3}[\s.-][0-9]{1,12})([\s.-]?[0-9]{1,4}?)$"></asp:RegularExpressionValidator>

it validate following phone numbers

local numbers 00 1234567, 000 1234567 or 04-1234567, 000-1234657

international numbers +000 00000000, +000-00000000, +00 00000000,

i also want to support numbers with out white space & with 00 for international numbers example

001234567, 0012312345678, 00123 12345678, 001212345678

Answer 1

Just make the in-between [\s.-] pattern as optional and add an optional 00 at the start.

^([\+]?(?:00)?[0-9]{1,3}[\s.-]?[0-9]{1,12})([\s.-]?[0-9]{1,4}?)$

DEMO

Answer 2

something like this:

^(\+?[0-9]{2,}[- ]?[0-9]{2,})$