What is the regex for a US phone number?

^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$ is a widely used flexible US pattern that accepts common formats including with or without country code, parentheses around area code, and various separators.

What regex matches international E.164 phone numbers?

^\+[1-9]\d{1,14}$ matches E.164 international format: a + followed by 2 to 15 digits, starting with a non-zero country code digit.

Should I normalise phone numbers before validation?

Yes. Strip spaces, dashes, and parentheses first if you want a consistent stored format. Validate the raw input with a flexible pattern, then normalise to E.164 for storage.

Can regex fully validate international phone numbers?

No. Phone number rules vary by country and region. Regex can catch format errors and obvious invalid values, but for comprehensive international validation use a library like libphonenumber.

How do I make the country code optional?

Wrap the country code portion in an optional group: (^\+[1-9]\d{0,2}\s?)?. This allows numbers with or without a country code prefix.

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Regex for Phone Number Validation — Patterns and Live Test

Phone number validation with regex is tricky because formats vary by country, region, and user convention. FixTools provides practical regex patterns for common phone number formats — US, international E.164, and formatted variants — with plain-English explanations and a live tester.

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Patterns for US, E.164 international, and flexible formats

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Handles common separators: spaces, dashes, dots, parentheses

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Plain-English explanation of each pattern component

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Test the flexible US phone pattern: ^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$ — it matches most US number formats including (555) 123-4567, 555-123-4567, and 5551234567.

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Step-by-step guide to regex for phone number validation — patterns and live test:

1
Choose the right pattern for your use case
For E.164 international numbers: ^\+[1-9]\d{1,14}$. For flexible US formats: ^[\+]?[(]?[0-9]{3}[)]?[-\s\.]?[0-9]{3}[-\s\.]?[0-9]{4,6}$. For digits-only validation: ^\d{10,15}$.
2
Load the pattern into the Regex Tester
Open FixTools Regex Tester and paste your chosen pattern.
3
Test with valid phone numbers
Test inputs like: +14155552671, (415) 555-2671, 415-555-2671, 415.555.2671.
4
Test with invalid inputs
Verify rejection of: too few digits, letters in the number, or invalid international code formats.
5
Adapt for your region
For non-US numbers, adjust the digit group lengths and optional prefix rules to match the format for your target country.