How many toll free numbers does ZipDX have?

ZipDX (ZU) manages 204 active toll free numbers as of 2026-10, according to the Somos toll free registry tracked by Resporgs.com.

How do I request a specific toll free number from ZipDX?

Resporgs.com hosts a request form for ZipDX at https://resporgs.com/ask/ZU. Fill in the number you want and your contact details. Bill Quimby reads every request and passes appropriate ones to the company that holds the number.

RespOrg directory

ZipDX

Q: What is ZipDX?

ZipDX is a US toll free Responsible Organization (RespOrg), code ZU. ZipDX (RespOrg code ZU) controls 204 US toll free numbers as of October 2026. That is down 20 (9%) since March 2018. Resporgs.com files it under Enhanced Voicemail Service. Based in Monte Sereno, CA.

Enhanced Voicemail Service

Request a specific #

Looking for a toll free number from ZipDX?

Tell me which number you want. I pass appropriate requests to the company that holds the number, and I reply within one business day. It's free to ask.

Request a number from ZipDX →

ZipDX (RespOrg code ZU) controls 204 US toll free numbers as of October 2026. That is down 20 (9%) since March 2018. Resporgs.com files it under Enhanced Voicemail Service. Based in Monte Sereno, CA.

Transfer network

How toll free numbers move between ZipDX (ZU) and other Resp Orgs, reconstructed from Somos registry snapshots. Larger nodes = more transfer volume; ZipDX is highlighted. Open the full interactive map →

Scroll to zoom, drag to pan, drag a node to reposition.

Transfer Funnel (acquired at a drop, then moved on) Off-hours fast pickup

Website, visit, full size

Based in Monte Sereno, CA, street view, full size

Based in Monte Sereno, CA, satellite, full size

Website: https://www.zipdx.info/ Domain since 2013 (12y)
Phone: (888) 947-3955 via web search: zipdx.info

At a glance

Active numbers

204

#329 of 479

Change over 4 years

-20

-8.9%

Opportunism Index

0.00%

Harvested 0 / acquired 18

Vanity matches

40.5%

Median inventory age

129 mo

10.8 years since last change

Sub-codes in use

ZUO01

Inventory by NPA

Click any NPA for total pool inventory across the industry.

By status

WORKING 190, 100.0%

Inventory age buckets

3–12 months 1, 0.4%
1–2 years 1, 0.4%
2–5 years 5, 2.2%
5+ years 183, 80.6%

Ages are measured from each number's last change in the Somos registry, that's the most recent activation, transfer, or status move. Not necessarily the date this RespOrg originally acquired it.

Request a manual history review of a specific toll free number →

Trajectory

Total active inventory Numbers harvested from disconnect pool that month

Show monthly numbers

Month	Inventory	Acquired	Lost	From spare	To spare
2018-03	224	0	0	0	0
2018-06	224	0	0	0	0
2018-09	224	0	0	0	0
2018-10	224	0	0	0	0
2018-11	224	0	0	0	0
2018-12	224	0	0	0	0
2019-01	224	0	0	0	0
2019-02	224	0	0	0	0
2019-03	224	0	0	0	0
2019-04	224	0	0	0	0
2019-05	224	0	0	0	0
2019-06	224	0	0	0	0
2019-08	208	0	16	0	16
2019-09	224	16	0	16	0
2019-10	223	0	1	0	0
2019-11	223	0	0	0	0
2019-12	223	0	0	0	0
2020-01	223	0	0	0	0
2020-02	223	0	0	0	0
2020-03	223	0	0	0	0
2020-04	223	0	0	0	0
2020-05	223	0	0	0	0
2020-06	223	0	0	0	0
2020-07	223	0	0	0	0
2020-08	223	0	0	0	0
2020-09	223	0	0	0	0
2020-10	223	0	0	0	0
2020-11	223	0	0	0	0
2020-12	223	0	0	0	0
2021-01	223	0	0	0	0
2021-02	223	0	0	0	0
2021-03	223	0	0	0	0
2021-04	223	0	0	0	0
2021-05	223	0	0	0	0
2022-05	223	0	0	0	0
2022-06	223	0	0	0	0
2022-07	223	0	0	0	0
2022-08	223	0	0	0	0
2022-09	223	0	0	0	0
2022-10	223	0	0	0	0
2022-11	223	0	0	0	0
2022-12	223	0	0	0	0
2023-01	223	0	0	0	0
2023-02	223	0	0	0	0
2023-03	223	0	0	0	0
2023-04	223	0	0	0	0
2023-05	223	0	0	0	0
2023-06	223	0	0	0	0
2023-07	223	0	0	0	0
2023-08	223	0	0	0	0
2023-09	223	0	0	0	0
2023-10	223	0	0	0	0
2023-11	223	0	0	0	0
2023-12	224	1	0	1	0
2024-02	224	0	0	0	0
2024-03	224	0	0	0	0
2024-04	224	0	0	0	0
2024-05	224	0	0	0	0
2024-06	224	0	0	0	0
2024-07	224	0	0	0	0
2024-08	224	0	0	0	0
2024-09	224	0	0	0	0
2024-10	224	0	0	0	0
2024-11	224	0	0	0	0
2024-12	224	0	0	0	0
2025-01	224	0	0	0	0
2025-02	224	0	0	0	0
2025-03	224	0	0	0	0
2025-04	224	0	0	0	0
2025-05	224	0	0	0	0
2025-06	224	0	0	0	0
2025-07	224	0	0	0	0
2025-08	224	0	0	0	0
2025-09	224	0	0	0	0
2025-10	224	0	0	0	0
2025-11	224	0	0	0	0
2025-12	224	0	0	0	0
2026-01	205	0	19	0	0
2026-02	205	0	0	0	0
2026-03	205	0	0	0	0
2026-04	205	0	0	0	0
2026-05	205	0	0	0	0
2026-06	204	1	2	0	0
2026-07	204	0	0	0	0
2026-08	204	0	0	0	0
2026-09	204	0	0	0	0
2026-10	204	0	0	0	0

Flow patterns (42-month cumulative)

Inbound (numbers acquired)

Direct transfer from another RespOrg	3.0
Harvested from disconnect pool	0.0
First assigned from spare pool	51.0
Reactivated own disconnects	0.0

Outbound (numbers lost)

Direct transfer to another RespOrg	6.0
Standard disconnect aging process (3+ months in DISC)	19
Abbreviated disconnect period (1–2 months in DISC)	0
Released directly to spare pool	32.0

Of the 19 disconnect episodes this RespOrg has sent through aging, 0% were abbreviated (1–2 snapshots in DISC status). This RespOrg lets most numbers age the full 3–4 months before release, normal pattern.

Top direct-transfer sources (INto ZU)

1.0

Haven Partners (CHP)

Top direct-transfer destinations (OUT of ZU)

ZX	2.0	Haven Partners (CHP)
LQ	1.0	Inteliquent

Summary

ZipDX is a powerful telephone conferencing service.

Top vanity holdings

Category:

844RITCHIE 844FRANKEL 855FRANKEL 866FRANKEL 800FRANKEL 877FRANKEL 888FRANKEL 855HURTBLST 844CAMTACA 855CAMPLED 844UH-HUH-45 855BANK-454 88843-ASILO 8554-TRACKS 888PLAN-004 888PLAN-001 888PLAN-002 888PLAN-001 888PLAN-004 855BANK-292 8779-NVIDIA 888PLAN-002 8775-NVIDIA 855CAMI-272 888432-SILO 888WISE-989 844PITCH-43 888WISE-919 888GEAR-456 888WISE-987 844UH-HUH-43 844ENTRADA 844TISHMAN 844TISHMAN 844TISHMAN 855CANKAYA 855BANKAYA 855CANKAYA 877SOULVAPES 877JASMARC 877KARMAPA 877KARMAPA 855ACM ICPC 855CAMIBRA 855COURTII 888ZHUBOBO 877LAKESII 855C COLILI 855ABOSLUT 855CAMSLUT 855CAMPKUT 855GTRACKR 877POT TAPE 800NEATIDO 855UKLUKLA 855UKLUKLA 844BANTABA 844BANTABA 844ABOUBBC 855CAMPLEE

Contact-form message

with a customer of ZipDX

Request a specific #