What Addrex does

Addrex, Inc. operates a global online marketplace for the transfer of rights to IPv4 number blocks, connecting holders of unused or excess IPv4 address space with network operators seeking additional IP capacity. Founded in 2009 and headquartered in Herndon, Virginia, the company serves a dual-sided market: on the supply side, organizations holding legacy IPv4 allocations (universities, enterprises, and institutions that received early allocations) seek to monetize unused blocks; on the demand side, ISPs, telecommunications providers, cloud infrastructure operators, data centers, and mobile network operators seek IPv4 addresses to support network growth amid IPv4 exhaustion.

The core product is the Addrex Marketplace, a self-service online platform available 24/7 that pre-qualifies both buyers and sellers, validates exclusive rights to IPv4 assets before listing, and maintains anonymity until the sale closing process. The platform integrates with all five Regional Internet Registries (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC) and provides standardized legal agreements, transaction document management, and RIR-specific transfer guidance. Addrex is positioned as the first ARIN-approved Qualified Facilitator and has facilitated the transfer of over 32 million IP addresses across more than 25 countries since inception, including the landmark court-approved Microsoft-Nortel transfer in 2011.

The business model is transaction-fee based, with free marketplace participation and free listing viewing; monetization occurs at transaction closing. Pricing is not publicly disclosed. Distribution is primarily self-service online combined with RIR and ICANN channel relationships, and the company supports multilingual interfaces across English, French, Spanish, German, Portuguese, and Simplified Chinese, with offices in the US, UK, and France.

Name

Addrex

Legal name

Addrex, Inc.

Website

https://addrex.net

Company type

Private

Founded year

2009

Operating status

Operating

Headcount range

11–50 employees

Short description

Addrex operates a global online marketplace facilitating IPv4 number block rights transfers between network operators and holders of unused address space across all five Regional Internet Registries. The 2009-founded, Herndon-based company has transferred over 32 million IP addresses across 25+ countries.

Ownership category

akta.pro rank

Headquarters

HQ city

Herndon

HQ country

United States

HQ region

North America

Offices2 records

Markets served

GTM type

B2B

Offering type

Digital Commerce or Content

Cost components

Personnel, Technology or R&D, Operations, Marketing or Sales

Revenue model

1. IPv4 Block Transaction Facilitation: Addrex facilitates the sale and transfer of IPv4 address block rights between buyers and sellers via the Addrex Marketplace. The company does not buy or resell IPv4 blocks itself, instead supporting the transfer of IP number block assets between counterparties. The platform charges no cost to become a participant and no fee to view listings.

Pricing tiers

Go-to-market motion2 records

Distribution channels2 records

Marketing channels4 records

Core offering

Addrex, Inc. operates a global online marketplace where holders of unused IPv4 number blocks can list their rights for sale and network operators can review and purchase them. The company facilitates the efficient sale and transfer of IPv4 address block rights (/24 Class C and larger) across each of the five Regional Internet Registries (RIRs). Addrex does not buy or resell IPv4 blocks; instead, it pre-qualifies sellers, validates their exclusive rights to IPv4 assets, and supports the legal transfer process through a standardized, market-proven workflow.

Product overview

Addrex operates a unified IPv4 Marketplace platform that serves as a global exchange connecting sellers of unused IPv4 number blocks with network operators seeking to acquire IP address space. The core Addrex Marketplace™ platform is supported by two service modules: Buyer Services (enabling network operators to access and purchase IP number blocks) and Seller Services (providing standardized processes, legal agreements, and transfer support for asset holders). The company also provides RIR Transfer Guidance as a support service, helping navigate the requirements of Regional Internet Registries (ARIN, APNIC, RIPE, LACNIC, AFRINIC). Addrex functions as a Qualified Facilitator recognized by ARIN, not as a buyer or reseller of IPv4 blocks.

Differentiator

Problem solved

Functional benefit

Brands

• Addrex Marketplace: The global online platform for buying and selling IPv4 number blocks, providing comprehensive transaction documents and transfer support.

Products and services

• Addrex Marketplace A global online marketplace where holders of unused IPv4 number blocks can list their rights for sale and network operators can review and purchase them. The platform facilitates efficient sale and transfer of IPv4 address block rights (/24 Class C and larger) with each of the five Regional Internet Registries (RIRs), and is available 24/7, 365 days a year.
• Buyer Services Provides network operators with a global marketplace for exclusive IP number blocks to help enable growth of network services; Addrex pre-qualifies all sellers and validates their exclusive rights to IPv4 block assets before listing them.
• Seller Services Minimizes administrative burdens on asset holders to sell IP number blocks in the Marketplace through a standardized process with fully vetted legal agreements and transfer support. Buyers in the marketplace are pre-qualified and vetted, and buyers and sellers remain anonymous until entering the sale closing process.
• RIR Transfer Guidance Guides clients through the nuanced requirements of each Regional Internet Registry (RIR) for IPv4 number block transfers, covering ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC. Addrex has successfully transferred IPv4 number block rights in over 25 countries.

Quantifiable outcome

• Over 32 million IP address numbers transferred between buyers and sellers
• +1 more outcomes

Named customers1 record

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature3 records

Partnerships

Three partnerships are on record, tiered core and flagship.

• ARIN (American Registry for Internet Numbers)coreTechnology or IntegrationAddrex is the first approved Qualified Facilitator recognized by ARIN, which serves Antarctica, Canada, parts of the Caribbean, and the United States. This official recognition validates Addrex's expertise in streamlining IPv4 transfer processes within the ARIN region.
• All Five Regional Internet Registries (RIRs)coreTechnology or IntegrationAddrex works with all five RIRs (AFRINIC, APNIC, LACNIC, RIPE NCC, and ARIN) as well as Internet-governing bodies like ICANN to help shape policy and procedures. This enables global IPv4 transfer facilitation.
• ICANN (Internet Corporation for Assigned Names and Numbers)flagshipStrategic or Co-development PartnerAddrex is very active in the industry and works with ICANN to help shape policy and procedures related to Internet number resources.

Scale indicators4 records

Recent moves6 records

Expansion highlights5 records

Others

• IPwe: IP transaction and management platform using blockchain-based infrastructure for IP rights registration and trading. Adjacent to Addrex in that both operate in IP rights transaction facilitation, though IPwe focuses on patents and broader digital IP assets rather than IPv4 blocks.
• Ocean Tomo: Intellectual property merchant bank and auction house operating across patents, trademarks, and intangible assets. Comparable as a marketplace and transaction intermediary for IP rights, though it focuses on patents rather than IPv4 number blocks specifically.

Direct peers

• IPTrading: Specialized IPv4 address broker and marketplace facilitating transfers between buyers and sellers. Directly comparable to Addrex in business model — transaction-fee-based brokerage of IPv4 number block rights across RIR regions.
• Prefix Broker: A dedicated IPv4 transfer broker providing marketplace and transaction services to buyers and sellers of IP address blocks. Directly comparable to Addrex in scope, customer base, and value proposition as a specialized IPv4 transaction intermediary.
• ServerHub: Infrastructure provider that operates an IPv4 marketplace as part of its broader hosting and IP services portfolio. Competes with Addrex in the IPv4 transfer market while also providing hosting services to a partially overlapping network operator customer base.
• V6 Broker: IPv4 and IPv6 broker/marketplace offering transfer facilitation services to network operators. Competes head-to-head with Addrex on global IPv4 block transactions and shares the same customer base of network operators and IP asset holders.
• IPv4 Global: One of the largest dedicated IPv4 transfer marketplaces, operating a broker model comparable to Addrex. IPv4 Global (acquired by Hilco Streambank) competes directly for the same buyers (ISPs, telcos, cloud providers) and sellers (enterprises, universities) across multiple RIR regions.

Broad incumbents

• Hilco Streambank: Broader IP and intangible asset disposition firm that acquired IPv4 Global, extending its services into the IPv4 transfer market. As a diversified IP services incumbent, it brings greater capital and a wider service portfolio than Addrex while still competing for IPv4 transfer mandates.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat4 records

Key risks5 records

Key highlights7 records

Customer concentration

• Xtwitter.com/addrexinc
• Facebookfacebook.com/addrexinc
• LinkedInlinkedin.com/company/addrex-inc-

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Addrex