Onvoy LLC - SD WARM
d/b/a Neutral Tandem-South Dakota LLC
Part of the Neutral Tandem group. 10 OCNs across 11 states · 27,664 blocks combined.
1 S Wacker Dr, Siute 200
Chicago, IL 60606-4614
Neutral Tandem
2001-02-07
2025-08-26
Long shot, but worth calling.
Onvoy LLC - SD issued these blocks a while back. Most of the numbers are probably already with customers, but it's worth calling any you're interested in. If a number isn't in service, it might still be available at Onvoy LLC - SD or one of their resellers.
About Neutral Tandem
Neutral Tandem operates as a neutral tandem provider, interconnecting competitive carriers including wireless, wireline, cable, and VoIP providers for local and long-distance traffic exchange, bypassing incumbent LEC tandems. It primarily serves wholesale carriers seeking diverse routing and PSTN gateway access across major US markets, connecting over 600 switches and 130 million numbers. The company has expanded globally with voice and data services following acquisitions.
- Parent: Sinch
- Founded: 2001
- Headquarters: Chicago, IL
- Services: neutral tandem interconnection, PSTN gateway, tandem diversity routing, carrier interconnect, voice transit
Sources: Neutral Tandem - Products, Competitors, Financials, Employees ... · [PDF] Tandem Diversity and the Public Switched Telephone Network: Neutral Tandem: An Independent Solution for Tandem Diversity · Interview with Neutral Tandem - YouTube
Toll-free side: Related toll-free RespOrg: Inteliquent (code HPC01). View on resporgs.com →
Carrier website
sinch.com: opens in a new tab
HQ: Chicago, IL
Block portfolio at a glance
By age
- Recent (8). Last 18 mo
- Medium (19)
- Old (483)
- Undated (3)
Footprint by state
Stronger blue = more blocks issued in that state. ● marks states with activity in the last 18 months.
- South Dakota SD · 513 · 8
Top area codes
Bars show total blocks; red overlay is recent.
Block assignments by year
Best vanity numbers from Onvoy LLC - SD's recent issuances
Numbers in blocks issued in the last 18 months whose digits spell a useful word. Filter by state and category to find one for your business. ★ marks Mike's curated standouts.
| Number | Spells | Category | State | Block issued |
|---|---|---|---|---|
| (605) 888-3733 ★ | UTTERED | Free | SD | 2025-03-20 |
Want one of these or something similar? Request the number from this carrier and we'll route the request.
Most recent assignments
Last 18 months. These blocks were issued by Onvoy LLC - SD since 2024-11-14.
| Number block | State | Rate center | Assigned |
|---|---|---|---|
| (605) 705-1XXX | SD | Sioux Fls | 2025-08-26 |
| (605) 888-3XXX | SD | Chamberlan | 2025-03-20 |
| (605) 317-XXXX | SD | Mitchell | 2025-02-17 |
| (605) 317-0XXX | SD | Mitchell | 2025-02-17 |
| (605) 317-1XXX | SD | Mitchell | 2025-02-17 |
| (605) 317-2XXX | SD | Mitchell | 2025-02-17 |
| (605) 317-3XXX | SD | Mitchell | 2025-02-17 |
| (605) 656-9XXX | SD | Mitchell | 2025-02-17 |
Sister OCNs in the Neutral Tandem group
Same customer-facing carrier, different state-registered OCN. Combined stats are on the Neutral Tandem group page.
| OCN | Company name on file | HQ state | Total | Recent |
|---|---|---|---|---|
| 224C | Onvoy LLC | IL | 8,314 | 406 |
| 464C | Onvoy LLC - OH | IL | 7,228 | 392 |
| 525E | Onvoy LLC - TN | IL | 3,788 | 166 |
| 896E | Onvoy LLC - KY | IL | 2,918 | 69 |
| 719E | Onvoy LLC - MS | IL | 2,104 | 35 |
| 689F | Onvoy LLC - ID | IL | 1,302 | 12 |
| 453F | Onvoy LLC - MT | IL | 905 | 4 |
| 454F | Onvoy LLC - ME | IL | 373 | 1 |
| 637E | Onvoy LLC - NH | IL | 219 | 7 |