Plan, vet, transfer, and activate IPv4 space with RDAP checks, escrow, registry steps, and routing protection.
IPv4 space is limited, and that scarcity has created a real market for address blocks. Even as IPv6 adoption grows, many bloggers, agencies, hosting teams, and small businesses still need IPv4 addresses for dedicated hosting, email delivery, or bringing their own addresses to a cloud provider.
This guide explains how to plan, vet, pay for, transfer, and activate an IPv4 block without getting lost in networking jargon.
Before you start: is ownership the right move?
You have three broad paths: own a block, lease one, or use addresses your hosting provider already manages.
Owning gives control and a long-term asset, but it brings registry steps and upfront cost. Leasing is faster and avoids a large purchase, though you do not build equity. Letting your host handle addresses is simplest, and many people never need more than that.
Some cloud providers now charge for public IPv4 addresses. That can make ownership worth considering for steady long-term needs. Whatever you choose, plan IPv6 in parallel so your setup has more room to grow.
What you’ll need in place
A registry account and eligibility
Addresses are managed by regional internet registries, or RIRs. In North America, that is ARIN. In Europe and parts of the Middle East, it is RIPE NCC. Across the Asia-Pacific region, it is APNIC. You will usually need an account with the registry that serves your region before you can receive a block.
Pre-approval basics
Most registries let you request pre-approval as a recipient before you find a seller. This is sometimes called a specified recipient or pre-approved transfer. For APNIC intra-region transfers, both source and recipient must be APNIC account holders, and pre-approvals stay valid for 24 months. Getting pre-approved early can reduce delays later.
Budget items to expect
Plan for the price of the block, registry fees, escrow fees, and optional broker fees if you use one. Prices vary, so treat any quote as a starting point and confirm the details in writing.
Step by Step: A Safe Way to Buy
Scope the block size you actually need
Start with how many addresses you realistically need. Registries set a floor. Under ARIN policy, the minimum IPv4 transfer size is a /24, which is 256 addresses. APNIC’s current minimum delegation size is also a /24. Buying smaller than a /24 is usually not practical, so size your plan around that floor.
Shortlist sellers or brokers
You can buy from a marketplace, directly from an owner, or through a facilitator. Compare how each party handles payment, paperwork, and the transfer itself. If you prefer a broker-managed route, you can buy IP addresses through a marketplace page that outlines payment via wire or escrow and describes a typical transfer workflow before you commit.
Verify ownership with RDAP
Before money changes hands, confirm that the seller controls the block. RDAP is a lookup tool that shows who holds a range and which registry manages it. The IANA RDAP IPv4 bootstrap file, published at data.iana.org/rdap/ipv4.json, maps address ranges to the authoritative RIR servers so you query the right source. Check that the holder name, prefix, and status match the contracts you are signing.
Check reputation and routing health
Some blocks carry a bad history. Run the block through a reputable IP and domain reputation checker to see whether any addresses appear on blocklists. A listing is not always a dealbreaker, but it can affect email delivery, hosting acceptance, and cleanup work after the transfer.
Routing health matters too. After the transfer, you will create routing protections.
Use licensed escrow for payment protection
Do not wire funds directly to an unknown seller. A licensed escrow service holds your payment until the transfer is verifiable. In a typical IPv4 escrow flow, the buyer funds escrow, the seller completes a verifiable transfer, the buyer accepts the transfer, and only then are funds released.
Submit transfer tickets and complete registry steps
With ownership and reputation checked and escrow in place, open a transfer request with the registry. ARIN recognizes 8.3 transfers within its region and 8.4 inter-RIR transfers, which means moving a block locally versus moving it between regions. ARIN documents that, after the registration agreement and fees are handled, completion occurs within two business days. RIPE NCC also authorizes and facilitates transfers and publishes inter-RIR procedures.
Bring the block online safely
Once the block is yours, protect it before you announce it. Create a Route Origin Authorization, or ROA, which is a signed record that authorizes a specific network to originate your prefix. Then set reverse DNS, update any allowlists that reference your IPs, and monitor reputation for two to four weeks while everything settles. Keep {{LINK_SLOT:web hosting security best practices}} on your checklist for the surrounding site setup too.
Regional notes at a glance
- ARIN (North America): Minimum transfer size is a /24. Waitlist-distributed space cannot be transferred for 60 months, except for Section 8.2 mergers and acquisitions.
- RIPE NCC: Authorizes and facilitates transfers of IPv4, IPv6, and AS numbers within its region, with documented inter-RIR procedures.
- APNIC: Minimum delegation is a /24. Both parties in an intra-region transfer must be account holders, and pre-approvals are valid for 24 months.
Red flags and common mistakes
A few warning signs should make you pause:
- A seller who will not use licensed escrow.
- RDAP records that do not match the names or prefixes in your contracts.
- An offer for fewer addresses than a /24, which most registries will not transfer.
- Claims of a clean reputation with no proof. Run your own blacklist check.
- Announcing a prefix before your ROAs exist, which leaves routing exposed.
Conclusion
A safe purchase is mostly about sequence. Plan the size you need, get pre-approved, verify the holder with RDAP, screen for blocklist history, pay through licensed escrow, and complete the registry steps before you create routing protections and go live. None of this requires deep networking expertise. It does require patience, documentation, and a checklist you follow in order. Pair the rollout with IPv6 planning, and you will have a setup that is easier to maintain over time.
FAQ
Do I need my own network identifier to use a new block?
To announce a block to the internet, it needs to be originated by a network, usually your own autonomous system number or a provider’s network. After the transfer, create a Route Origin Authorization that authorizes the right network to originate your prefix.
What if the block I’m offered appears on a blocklist?
Check it before you buy. A listing is not automatically a dealbreaker, but it may require cleanup and could affect email or hosting use. Factor that work into your price, timeline, and decision.
Can I lease instead?
Yes. Leasing can fit temporary needs if routing, reputation, and reverse DNS responsibilities are clear.
When should I plan IPv6?
Start now. It reduces future pressure on limited public addresses and gives your setup more room.
