The Market for IPv4 Addresses: Who’s Buying, Who’s Selling?

For most internet users, an IP address feels like plumbing: invisible, boring, and always there. For cloud providers, hosting companies, telecom operators, email platforms, VPNs, and fast-growing SaaS businesses, IPv4 addresses have become something else entirely: scarce infrastructure with a real market price.

That market exists because IPv4 was built with a hard ceiling. The protocol uses 32-bit addresses, giving the internet roughly 4.3 billion possible IPv4 addresses, many of which are reserved or otherwise unavailable for normal public use. The central global IPv4 free pool was depleted in February 2011, when IANA distributed the last available /8 blocks to the five Regional Internet Registries.

IPv6 was supposed to make this scarcity irrelevant. In the long run, it probably will. But in the meantime, much of the commercial internet still depends on IPv4 compatibility. The result is a strange, semi-formal economy: not exactly a black market, not fully transparent like a commodities exchange, but a brokered transfer market where address blocks can be bought, sold, leased, financed, cleaned, and reputationally damaged.

From Technical Resource to Balance-Sheet Asset

IPv4 addresses were not originally handed out like property. Early internet organizations, universities, telecoms, defense contractors, and technology companies received large allocations when address space seemed abundant. Some of those legacy holders still control blocks far larger than they need.

Today, those blocks can be worth millions.

Market pricing varies by region, block size, routing quality, and reputation history. Public broker and marketplace data in 2026 commonly puts purchase prices in the tens of dollars per address, with larger blocks often trading at lower per-IP prices than small blocks. One recent market estimate placed /16 blocks, which contain 65,536 IPv4 addresses, around $18–$28 per address, or roughly $1.18 million to $1.84 million per /16. Smaller /24 blocks can command higher per-address prices because they are easier to route and easier for smaller buyers to absorb.

That means an old corporate or university allocation that once looked like an administrative artifact may now look like a real estate portfolio. For sellers, the question is no longer “Do we still need these addresses?” but “Are we sitting on a seven-figure asset?”

Who’s Buying?

The biggest buyers tend to be organizations whose growth is constrained by IPv4 scarcity.

Cloud providers need public IPv4 addresses for virtual machines, load balancers, NAT gateways, managed databases, Kubernetes clusters, customer-facing endpoints, and bring-your-own-IP services. Hyperscale clouds have pushed customers toward more efficient IPv4 use, and AWS began charging $0.005 per IP per hour for all public IPv4 addresses in February 2024, whether attached to a service or not. Google Cloud also changed external IPv4 pricing in 2024 and charges for static and ephemeral external IP addresses under its VPC pricing model.

Hosting companies and data centers are another major buyer group. Their customers often still expect dedicated public IPv4 addresses for servers, firewalls, SSL termination, mail servers, game servers, VPN endpoints, and legacy applications. Even when a provider supports IPv6, customer demand for IPv4 remains sticky.

Telecoms and ISPs buy IPv4 space to serve broadband, mobile, and enterprise customers. Carrier-grade NAT reduces the number of public addresses required, but it introduces complexity, logging burdens, law-enforcement response challenges, and application breakage.

Email service providers, marketing platforms, CDNs, VPN operators, residential proxy networks, and cybersecurity vendors also compete for clean address space. For them, the address is not just a routeable number. It is a reputation-bearing identity.

Who’s Selling?

Sellers are often organizations that received generous allocations before the modern scarcity era.

Universities are classic examples. Many received large address blocks decades ago to support research networks, campus systems, and early internet experiments. Some still use their allocations heavily; others have consolidated, moved workloads to cloud providers, adopted NAT, or migrated portions of their infrastructure to IPv6.

Old corporations are another source. Mergers, bankruptcies, divestitures, and IT modernization projects can uncover unused IPv4 space. A company that once operated its own global network may now outsource hosting, SaaS, and remote access, leaving address blocks underused.

Telecoms, cable companies, and hosting firms also sell or lease addresses when they restructure networks or discover stranded inventory. In some cases, sellers are not abandoning IPv4; they are arbitraging it. They may sell large blocks and lease back smaller amounts, or lease unused ranges while retaining registration.

Government agencies and research institutions can be sellers too, though their processes are usually slower because of procurement rules, public accountability, and internal approvals.

The Brokers in the Middle

The IPv4 market is broker-driven because a transfer is not just a payment. It requires registry paperwork, title-like diligence, routing checks, contract terms, escrow, and sometimes cross-border policy compliance.

Regional Internet Registries such as ARIN, RIPE NCC, APNIC, LACNIC, and AFRINIC maintain registry records and transfer policies. In the ARIN region, specified transfers require the recipient to qualify under policy, including need-based requirements. ARIN says transfer recipients must demonstrate that 50 percent of the requested IPv4 addresses will be used within 24 months and that 50 percent of previous assignments or allocations are efficiently used. ([arin.net][5]) ARIN also maintains a transfer process and notes that source entities are subject to restrictions, including a 12-month limitation after receiving IPv4 resources by transfer or allocation, with certain ownership exceptions.

This is where brokers add value. They source buyers and sellers, help structure agreements, advise on registry requirements, coordinate escrow, and investigate whether the block has a clean chain of registration. ARIN also refers to “Qualified Facilitators” who have undergone its vetting process to assist with IPv4 address and ASN transfers.

Well-known participants in the broader market include IPv4.Global, IPXO, Hilco Streambank, Prefixx, Brander Group, IPTrading, and regional specialists. Some focus on outright sales. Others emphasize leasing. Some run auction-style marketplaces where prices are visible; others work through private negotiated transactions.

The broker’s pitch is simple: IPv4 may be technical, but the transaction is financial, legal, and operational.

Buying an Address Is Not Like Buying a Server

The riskiest assumption in the IPv4 market is that all addresses are interchangeable.

They are not.

An IPv4 block has a history. It may have been used by a legitimate university, an email spam operation, a botnet host, a bulletproof hosting provider, a VPN network, a scraping platform, or a malware command-and-control operation. Even after the official registration changes, that history can linger across blocklists, fraud models, search engines, email providers, payment platforms, and security vendors.

Spamhaus defines IP reputation as an assessment of the trustworthiness of an IP or IP range, based on signals about who used it, what it did, where it appeared, and when. Its Spamhaus Blocklist includes IPs and ranges identified in malicious activity such as spam, snowshoe spam, malicious hosting, bulletproof hosting behavior, or hijacked IP space.

For an email sender, a dirty block can mean poor inbox placement or outright rejection. For a SaaS provider, it can mean customers encounter CAPTCHAs, failed logins, fraud checks, or geolocation errors. For a cloud provider, it can mean abuse complaints begin before the first customer has even launched a workload.

Google’s own support materials note that “unusual traffic” can trigger a reCAPTCHA challenge to confirm that the user is not a robot. ([Google Help][11]) Enterprise network providers also warn that Google CAPTCHA and geolocation issues can arise when traffic patterns look automated or when shared egress IPs create concentrated activity.

That is why “clean” IPv4 space commands a premium. The buyer is not only buying routeability. It is buying the absence of baggage.

The Rise of IP Reputation Management

As IPv4 became a market, IP reputation management became an operational discipline.

A buyer now has to ask questions that sound more like anti-money-laundering diligence than network engineering:

Has this block appeared on major email blocklists? Was it used for snowshoe spam? Is it listed as residential, hosting, proxy, VPN, mobile, or enterprise space in commercial reputation databases? Does the geolocation point to the wrong country? Are there stale WHOIS records? Are reverse DNS records still associated with the prior owner? Are routing objects accurate? Has the block been hijacked or announced suspiciously in the past?

A good acquisition process includes pre-closing scans against public and commercial reputation datasets, review of historical BGP announcements, registry validation, abuse-desk checks, RPKI and route-object planning, reverse DNS cleanup, and a staged warm-up period before the range is used for sensitive workloads.

Email senders know this best. A newly acquired block cannot simply be pointed at high-volume outbound mail and expected to perform. It has to be warmed gradually, authenticated with SPF, DKIM, and DMARC, monitored for bounces and complaints, and separated by customer or traffic quality. Reputation is accumulated, not declared.

The same logic increasingly applies outside email. Search engines, fraud platforms, payment processors, social networks, ticketing systems, gaming platforms, and streaming services all use IP-derived signals. An address range that works perfectly for web hosting may perform badly for account creation, login traffic, API automation, or outbound messaging.

Leasing: Flexibility With a Catch

Not every buyer wants to purchase IPv4 space outright. Leasing has become attractive for companies that need addresses quickly, temporarily, or without a large capital outlay.

Leasing can be useful for cloud migration, seasonal infrastructure, lab environments, customer-specific deployments, or providers that want to match address cost to monthly revenue. Recent market estimates put lease prices commonly in the range of a few tenths of a dollar per IP per month, with variation by block size and region.

But leasing adds risk. The lessee may not fully control the address history, registry relationship, or long-term availability. The lessor may reclaim the block. A prior lessee may have abused it. A future lessee may damage adjacent reputation. Registry policy and routing legitimacy can also be more complicated than in a clean ownership transfer.

For businesses where IP reputation is mission-critical, leasing can be a false economy unless contracts clearly cover permitted use, abuse response, termination rights, reputation remediation, routing authority, and registry documentation.

Why IPv6 Hasn’t Killed the Market

IPv6 offers a vastly larger address space, and the technical answer to IPv4 scarcity is obvious: deploy IPv6 everywhere. But markets are shaped by compatibility, not elegance.

IPv6 adoption has grown for consumer access networks, mobile carriers, hyperscale platforms, and major content providers. Yet many enterprise applications, network appliances, embedded systems, industrial systems, SaaS integrations, security tools, and customer environments still assume IPv4. IPv6-only services often need translation, proxies, or dual-stack support to reach IPv4-only users and systems.

As long as customers, partners, bots, APIs, devices, and old software expect IPv4, IPv4 will retain value.

The market will probably not vanish suddenly. Instead, it may become more segmented. Clean, routable, well-documented space will remain valuable. Dirty or awkwardly sized space may trade at a discount. Small blocks may stay expensive because they are accessible to more buyers. Large blocks may behave more like institutional assets, with pricing tied to cloud demand, leasing yields, and the pace of IPv6 substitution.

The Future: Scarcity, Reputation, and Governance

The IPv4 market sits at an uncomfortable intersection. It is a scarcity market built on a public technical resource. It rewards old allocations, favors organizations with capital, and creates incentives to monetize unused space. At the same time, it helps keep the internet functioning during a long transition to IPv6.

The next phase will likely be defined by three forces.

First, cloud pricing will make IPv4 cost more visible. When major providers charge separately for public IPv4 usage, engineering teams suddenly have a reason to audit idle addresses, consolidate endpoints, adopt private networking, and consider IPv6. AWS’s public IPv4 charge is one example of that shift from hidden scarcity to explicit line item.

Second, reputation will become inseparable from valuation. A block’s price will increasingly reflect not just size and registry region, but cleanliness, geolocation accuracy, prior routing, abuse history, and email deliverability.

Third, governance will matter more. Buyers will demand clearer transfer histories, stronger routing authentication, better abuse contacts, and warranties around reputation. Brokers that can verify provenance and reduce operational risk will have an advantage over those that simply match buyers and sellers.

IPv4 addresses used to be numbers. Now they are assets with histories.

And in this market, the most expensive address is not always the one with the highest price. It may be the cheap one that arrives already poisoned.