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Original
2026-01-01
Modified
2026-03-10
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<p><strong>E.123 international</strong>is a standard for formatting phone numbers, web addresses, and<a>email addresses</a>established by the International Telecommunication Union (ITU). Phone numbers that use this format (e.g., +1 123 456 789) are designed to ensure consistency and clarity in international communications.</p>
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<p><strong>E.123 international</strong>is a standard for formatting phone numbers, web addresses, and<a>email addresses</a>established by the International Telecommunication Union (ITU). Phone numbers that use this format (e.g., +1 123 456 789) are designed to ensure consistency and clarity in international communications.</p>
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<h2>How does the E.123 international phone number format work?</h2>
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<h2>How does the E.123 international phone number format work?</h2>
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<p>The E.123 international phone number format consists of:</p>
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<p>The E.123 international phone number format consists of:</p>
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<ol><li><strong>Plus sign (+):</strong>The standard prefix that indicates the subsequent number sequence is an international telephone number.</li>
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<ol><li><strong>Plus sign (+):</strong>The standard prefix that indicates the subsequent number sequence is an international telephone number.</li>
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<li><strong>Country code:</strong>A numerical code representing a specific country or region.</li>
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<li><strong>Country code:</strong>A numerical code representing a specific country or region.</li>
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<li><strong><a>Numbering Plan Area</a>(NPA) code:</strong>The 1- to 3- digit area code identifying the specific geographic region within a country. Note that this is also called a “dialing code” in some regions.</li>
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<li><strong><a>Numbering Plan Area</a>(NPA) code:</strong>The 1- to 3- digit area code identifying the specific geographic region within a country. Note that this is also called a “dialing code” in some regions.</li>
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<li><strong>Local number:</strong>The unique number assigned to a specific person within a numbering plan area.</li>
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<li><strong>Local number:</strong>The unique number assigned to a specific person within a numbering plan area.</li>
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</ol><h2>E.123 international vs. E.123 national</h2>
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</ol><h2>E.123 international vs. E.123 national</h2>
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<p>While E.123 international includes a plus sign (+) followed by the country code and phone number, E.123 national uses parentheses to separate the area code and local number.</p>
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<p>While E.123 international includes a plus sign (+) followed by the country code and phone number, E.123 national uses parentheses to separate the area code and local number.</p>
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<p>Unlike the plus sign in international numbers, the parentheses in E.123 national are not mandatory and can be omitted when dialing from within the same country.</p>
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<p>Unlike the plus sign in international numbers, the parentheses in E.123 national are not mandatory and can be omitted when dialing from within the same country.</p>
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<p>E.123 national is regulated by the same standard as E.123 international, which provides the formatting guidelines for telephone numbers, email addresses, and web addresses published by the ITU.</p>
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<p>E.123 national is regulated by the same standard as E.123 international, which provides the formatting guidelines for telephone numbers, email addresses, and web addresses published by the ITU.</p>
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<h3>Additional resources</h3>
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<h3>Additional resources</h3>
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<ul><li><a>What is a sign-up form</a>?</li>
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<ul><li><a>What is a sign-up form</a>?</li>
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<li><a>What is a promo code</a>?</li>
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<li><a>What is a promo code</a>?</li>
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<li><a>What is express consent</a>?</li>
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<li><a>What is express consent</a>?</li>
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<li><a>What is a special character</a>?</li>
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<li><a>What is a special character</a>?</li>
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</ul>
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</ul>