TL;DR: For most small businesses, porting a phone number to VoIP takes 5–7 business days from the day you sign the Letter of Authorization (LOA). The FCC requires carriers to complete a “simple” wireline port in 1 business day and a “non-simple” port (multiple lines, key-system, toll-free) in 4 business days, but real-world timelines stretch to a week because of CSR mismatches, pending orders on the losing carrier’s account, and toll-free SMS records. Your phones keep working the entire time — cut-over only happens at midnight on the scheduled FOC date.
The honest answer: 5–7 business days for a normal port
If you have a single landline, a basic 4-line key system, or 10 VoIP DIDs and no surprises on the account, the number will ring on your new system within a week of signing the LOA. About two-thirds of small-business ports close in 5–7 business days; the other third hit a rejection on the first submission, get corrected, and close in 8–12 business days.
The FCC’s 47 CFR § 52.35 sets legal floors all U.S. carriers must meet: 1 business day for a simple port (one wireline number, no special routing) and 4 business days for a non-simple port (multiple numbers, hunt groups, toll-free). Most providers quote 5–7 days because that buffer absorbs LOA validation, the CSR pull, and the FOC (Firm Order Commitment) from the losing carrier.
What actually happens during those 7 days
The clock starts when your new provider submits a clean Local Service Request (LSR) — not when you sign up. Here is the typical sequence for a 10-line port:
- Day 0: You email a recent phone bill and sign the LOA. We pull your Customer Service Record (CSR) to match the billing name, address, and BTN character-for-character, then submit the LSR.
- Day 1–3: The losing carrier validates the LOA against their CSR. Any mismatch — a missing comma, a wrong suite number — triggers a Port Out Reject; we have 24–48 hours to refile.
- Day 3–5: The losing carrier issues a Firm Order Commitment (FOC) with the cut-over date and time.
- Day 5–7 (midnight): The number cuts over to your new VoIP trunk. Test in the first 15 minutes — if calls fail, we open a trouble ticket while the route is still warm.
When porting takes longer than 7 days
About 30% of business ports stretch past the 7-day mark. The most common reasons, in order of how often we see them at OneCloud:
- Business name doesn’t match the CSR (40% of rejections). “Bob’s Bagel Shop” vs “Bob’s Bagel Shop, LLC” is enough to reject. Bandwidth’s porting team has a breakdown of the most common port rejections and name mismatch tops the list.
- Pending order on the losing account (20%). A recent feature add, address change, or open service ticket locks the account. Carriers must close the pending order first — adds 3–5 days.
- Toll-free numbers (15%). Toll-free goes through RespOrg, not LNP. Plan on 7–10 business days; if there are active SMS records, Campaign Registry can push it to 14–21 days.
- Past-due balance (10%). Even $40 past-due can stall the release until paid current.
- Wrong account number or PIN (10%). Some carriers (T-Mobile, Spectrum Business) require a port-out PIN you have to generate from their portal.
- Complex routing (5%). Hunt groups, ring-downs, and PRIs need a separate carrier-to-carrier coordination call.
A real example: 12-line dental office port (Plano, TX)
In March 2026 a 12-line Plano dental office migrated from a regional cable carrier to OneCloud Networks: 12 DIDs, one hunt group, one fax line. LSR submitted Monday 10:42 a.m. Central with a clean CSR match. FOC issued Wednesday afternoon for a Friday-midnight cut-over. Total elapsed: 4 business days. Zero lost calls — we held call forwarding from the old trunk for 24 hours after cut. Total port fees: $25 per number, billed by the losing carrier ($300).
Common porting mistakes that cost a week
If you remember nothing else, remember these:
- Don’t cancel your old service before the port closes. Once the number is disconnected, it goes into “aging” status — up to 365 days for business numbers per FCC rules — and it cannot be ported. Always cut, then cancel.
- Use a recent bill (within 30 days) for the LOA. Stale bills trigger CSR mismatches because the carrier may have updated their record since.
- Submit before 1 p.m. local time. LSRs received after 1 p.m. don’t start the clock until the next business day at 8 a.m.
- Pre-pay any outstanding balance. Even $40 past-due is enough to stall a release.
- Don’t change your address or company name with the losing carrier in the 30 days before porting. The pending-order lock will eat 3–5 days.
Porting to OneCloud Networks specifically
Our standard timelines: 5–7 business days for 1–20 lines, 7–10 days for 20+ lines or hunt-group complexity, and 7–14 days for toll-free. We do not charge a port-in fee — the losing carrier may charge $10–$30 per number on the final bill. Cut-over happens at midnight Central on the FOC date, so business-hours downtime is effectively zero.
Frequently asked questions
Can I keep my phone number when switching to VoIP?
Yes. The FCC requires every U.S. carrier to release any portable number on request, per the FCC consumer porting guide. For business DIDs in any U.S. metro, geography is almost never a blocker.
Will my phones stop working during the port?
No. Your old service runs uninterrupted until the midnight cut-over on the FOC date. Keep the old service active for 24–48 hours post-cut as a safety net.
Can my old carrier refuse to release the number?
They cannot refuse a properly submitted port. They can reject for valid reasons (name mismatch, pending order, past-due balance) — correctable in 24–48 hours. Outright refusal is an FCC violation; file at fcc.gov/consumer-complaints.
How much does porting cost?
The gaining carrier rarely charges. Losing carriers often charge $10–$30 per number; toll-free RespOrg changes run $5–$15. Budget $25 per DID worst-case. OneCloud Networks does not charge a port-in fee.
What if I have an AI receptionist on the old line?
Rebuild it on the new platform before cut-over. If you’re moving to OneCloud’s AI receptionist, we configure the greeting, hours, FAQ, and routing rules 48 hours before the port closes so the AI goes live the moment the number cuts.
Next step
If you have a recent bill and you know your authorized signer, OneCloud Networks can usually get an LSR out the door the same day you sign up. Most small-business owners we work with see their number ring on the new system within a week, with zero downtime in between. Call 844-450-3527 for a 10-minute port-readiness check, or browse our business phone system plans.
