Despite years of talk about IPv6, the internet still runs heavily on IPv4, and demand for those addresses has not gone away. With the original pool long exhausted, organizations that need more address space now turn to a secondary market to acquire it. If your network is expanding, understanding how to buy IPv4 addresses safely is increasingly part of doing business.
This guide explains why IPv4 still matters, what buying an address block actually involves, how the transfer process works and what to check before you commit.
Why IPv4 still matters
IPv4 provides roughly 4.3 billion addresses, which seemed enormous when the protocol was designed but proved far too few for a connected world. The regional internet registries handed out the last of their free address space years ago, creating a genuine scarcity.
IPv6 was created to solve this with a vastly larger address space, and adoption continues to grow. Even so, much of the internet’s infrastructure, hardware and software still depends on IPv4 for compatibility, so most organizations cannot simply switch over. That ongoing reliance is what sustains a secondary market where IPv4 address blocks are bought, sold and leased.
For a growing ISP, hosting provider or enterprise, acquiring additional IPv4 space is often the most practical way to support expansion without breaking existing systems.
What does it mean to buy IPv4 addresses?
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Buying IPv4 is slightly different from buying a typical asset. Address blocks are ultimately administered by the regional internet registries, such as ARIN, RIPE, APNIC, LACNIC and AFRINIC, and organizations hold the rights to use them rather than owning them outright.
When you buy IPv4, you are acquiring the rights to a block of addresses through an official transfer recorded by the relevant registry. Blocks are sized using CIDR notation, from a small /24 of 256 addresses up to far larger allocations, and the registry updates its Whois records to reflect the new holder once the transfer is approved.
Because the process is governed by registry policies and involves verifying ownership, it pays to understand the steps before you start.
How the IPv4 buying process works
While the details vary by registry, the path to buying an address block generally follows a clear sequence:
- Pre-approval, where you confirm with the registry that your organization is eligible to receive the size of block you need
- Sourcing a block, finding a seller with clean, available addresses in the right region
- Contracts, putting a purchase agreement in place that sets the terms of the transfer
- Payment, typically handled by wire transfer or through an escrow service to protect both parties
- Registry transfer, where buyer and seller submit transfer tickets, the registry verifies ownership and approves the move
- Whois update, after which the addresses are recorded under your organization and funds are released to the seller
The timeline often runs a couple of weeks depending on the registry and the parties involved.
Why many buyers work with a broker
The market can be opaque. Finding a legitimate seller, confirming they own the addresses free and clear, checking the block is clean and navigating registry policy is a lot to manage alone, which is why many organizations work with a specialist broker to buy IPv4 safely. Brander Group, an IPv4 and connectivity brokerage operating since 2007, facilitates 50 to 80 IPv4 transfers each month across ARIN, RIPE and APNIC for clients in more than 60 countries.
A broker’s value lies in handling the parts that are easy to get wrong. Brander Group qualifies each seller to confirm clean ownership, runs every address against more than 100 global blacklists and provides a detailed report, manages contracts and the full transfer process, and uses a proprietary approach to uncover legacy address space that has sat dormant for years. Blocks ranging from a /24 up to a /12 are handled through its managed service, with payment secured by wire or escrow.
For a buyer, that support turns a complex, high-value transaction into a guided process with far less risk of a costly mistake.
What to check before you buy
Whether you work with a broker or not, a few checks protect you. They are worth confirming for any block you consider.
First, verify the addresses are clean. IPs that appear on blacklists can cause email delivery and reputation problems, so a thorough blacklist report matters. Second, confirm legitimate ownership, ensuring the seller genuinely holds the rights and the block is free of disputes or liens. Third, match the region to your needs, since registry policies differ and the block should suit where and how you intend to use it.
Getting these right upfront avoids inheriting someone else’s problems along with the addresses.
Should you buy or lease IPv4?
Buying is not the only option. As prices and interest rates have shifted, leasing IPv4 has become a popular alternative for organizations that want flexibility or a lower upfront cost.
Leasing lets you use address space for a defined period without the larger capital outlay of a purchase, with arrangements ranging from month to month up to longer multi-year terms. Buying, on the other hand, suits organizations that want a long-term asset and the certainty of holding the rights themselves. The right choice depends on your budget, your timeline and how permanent your need for the addresses is.
The bottom line
IPv4 remains essential infrastructure, and a healthy secondary market means address space is available if you know how to buy it safely. The keys are understanding that you are acquiring registry-recorded rights, following the transfer process carefully, and verifying that any block is clean and legitimately owned.
For many organizations, working with an experienced broker is the simplest way to navigate that complexity and complete a secure transfer. Whether you choose to buy or lease, approach the market informed, confirm the details, and treat the purchase with the same care as any other significant investment in your network.
