[Glossary](https://telxpress.com/glossary/) / Phones # Number porting **Number porting** is the process of moving your existing phone numbers from one carrier or phone provider to another, so a change of phone system never means a change of the numbers your customers know. - Phones - Updated October 11, 2026 - Written by the Telxpress advisory team 01 In depth ## What it is, why it matters and *what to ask a vendor* Federal law gives carriers a duty to provide number portability, and FCC rules set porting intervals: simple ports must complete within one business day, while ports involving many numbers or complex arrangements take longer and are scheduled. The new provider submits the request with a letter of authorization and a recent bill, and the old carrier releases the numbers on the agreed date. For a growing business porting is the riskiest hour of a phone project: if the details do not match the old carrier's records exactly, the port is rejected and the cutover slips. Toll-free numbers, fax lines, alarm lines and numbers bundled with internet service each need attention. Never cancel the old service before the port completes, or the numbers can be lost. Ask the new provider who manages the port end to end, what information they need from your current bill, how they handle rejections, whether temporary numbers are used during the transition, and how the port date is coordinated with installing phones. Ask the old carrier about contract terms and early termination fees before you start. 02 Related terms ## Terms that usually come up *alongside it* - Phones ### [Cloud phone system](https://telxpress.com/glossary/cloud-phone-system/) A cloud phone system is a business phone service hosted by a provider and delivered over the internet, so phones, apps and features are managed through a web portal rather than hardware in your office. - Phones ### [UCaaS](https://telxpress.com/glossary/ucaas/) UCaaS (unified communications as a service) is a cloud subscription that combines business phone calling, video meetings, team messaging, voicemail and often contact-center features in one platform managed by the provider. - Phones ### [SIP trunk](https://telxpress.com/glossary/sip-trunk/) A SIP trunk is a virtual phone line delivered over the internet that connects your own phone system (an on-site or hosted PBX) to the public telephone network, replacing traditional analog or digital carrier lines. - Phones ### [E911](https://telxpress.com/glossary/e911/) E911 (enhanced 911) is the emergency-calling capability that sends a caller's phone number and location to dispatchers; for business phone systems, Kari's Law and RAY BAUM's Act set specific federal requirements. 03 At Telxpress ## Where this shows up *at Telxpress* The pages and articles where this term does real work: what we advise, build and support. - Page ### [Business VoIP & Cloud Phone Systems in Irvine](https://telxpress.com/solutions/business-technology/phone-systems/) VoIP, cloud phone systems, UCaaS and SIP trunks from Yealink, Nextiva, Avaya, Yeastar and Polycom, installed, supported and ready for AI call handling. - Page ### [Contact Telxpress in Irvine, CA | 24/7 Support Line](https://telxpress.com/contact/) Call (949) 861-4500 any time, email info@telxpress.com or visit 230 Goddard, Irvine. Office hours, map, contact form and consultation booking. - Article ### [Preparing Your Office Phone System for the New Year](https://telxpress.com/insights/preparing-your-office-phone-system-for-the-new-year/) A ten-step new-year checklist for the office phone system: review the setup, update software, audit routing and voicemail, read call reports, train, secure, test and back up. 04 Sources ## Public *references* The standard or law this definition rests on, as published by its owner. Fetched and checked on the review date above. - [47 CFR 52.35, porting intervals (Cornell LII)](https://www.law.cornell.edu/cfr/text/47/52.35) law.cornell.edu - [47 U.S.C. 251, interconnection and number portability duty (Cornell LII)](https://www.law.cornell.edu/uscode/text/47/251) law.cornell.edu Next step ## Want This Applied *to Your Business?* Book a free 30-minute AI readiness consultation. You'll leave with three AI opportunities specific to your business, whether you work with us or not. [Book My Free Consultation](https://telxpress.com/book/) [Take the Free AI Readiness Assessment](https://telxpress.com/ai-readiness/) [Or call 24/7: (949) 861-4500](tel:+19498614500) Last reviewed: October 11, 2026. Published by Telxpress, Irvine, CA.