Tools

VoIP number formatter and dial-pattern tester

Last reviewed September 4, 2026

Use this private browser tool to prepare a number for a dial plan and check which patterns match it. Nothing you enter is sent to Phone Guides.

E.164 number formatter

Build an international-format number without sending it anywhere. Enter the country calling code without a plus sign. Enter the prefix removed for a national call, usually 0. If the number already starts with +, the tool checks it as entered.

Country calling code

National prefix to remove

Phone number

Enter a number to create an E.164 candidate.

Dial-pattern tester

Test a number against simple, vendor-neutral patterns. Use one pattern per line. Digits match themselves, X matches 0–9, N matches 2–9, Z matches 1–9, and brackets define a range such as [2-5]. Spaces, hyphens, and brackets around the phone number are ignored.

Number to test

Patterns, one per line

Enter a number and at least one pattern.

Understand the result

An E.164 number starts with a plus sign and can contain no more than 15 digits. The formatter creates a candidate only. It cannot confirm that the number exists, is assigned, or has the correct length for a particular country.

Dial-pattern symbols are not identical on every phone system. This tester uses only the syntax explained beside the tool. Translate the result into your system’s documented syntax before making a change.