Public IPv4 addresses have become a real line item. Cloud providers often bill for them by the hour, so a few hundred addresses running all year deserve the same review as compute or storage.
The free supply ran dry years ago. IANA handed out its last blocks to the regional registries in February 2011, and most of those registries have since exhausted their own pools. Today, transfers between organizations are the main way to get portable IPv4 space.
This guide covers what you actually get when you buy, how the regional registries differ, what to check before paying and how to hand over routing without surprises.
Key Takeaways
- Buying IPv4 transfers registration and use rights under registry policies, not unrestricted ownership.
- A /24 (256 addresses) is the smallest block widely accepted for public routing, so plan around it.
- Each registry has its own eligibility rules, fees and holding periods.
- Routing records, blocklists and geolocation matter as much as the registry record.
- Compare total cost, including registry, transaction and operating charges, before you buy.
What Buying IPv4 Really Means
When you buy a block, you pay the current holder to transfer its registration and use rights to your organization. Those rights stay subject to the policies of the relevant Regional Internet Registry (RIR). You can’t treat the block like property you use or resell without restriction.
Blocks are written in CIDR notation. A /24 holds 256 addresses, a /23 holds 512 and a /22 holds 1,024, with each step down doubling the count. Blocks smaller than a /24, such as a /25, are commonly filtered from the global routing table.
There are five RIRs, and this guide covers the four most buyers deal with. ARIN serves the United States, Canada and parts of the Caribbean. RIPE NCC covers Europe, the Middle East and Central Asia, APNIC covers Asia Pacific and LACNIC covers Latin America and parts of the Caribbean.
Buy, Lease or Wait?
Buying makes the most sense for stable, long-term workloads. Think production hosting, a SaaS platform with fixed endpoints or services that customers have added to allowlists. Holding your own block can let you change network providers without renumbering, subject to the new provider’s routing requirements.
Your own block can also support bring-your-own-IP (BYOIP) with a cloud provider. Check that the specific service accepts your block and whether BYOIP actually removes the public IPv4 charge, since billing treatment varies.
Leasing suits uncertain demand or short projects. You pay a recurring fee and return the space at the end, so plan for renumbering if the arrangement stops.
Waiting is a third option. ARIN runs a waiting list for qualifying requests, but timing is uncertain, so don’t build a launch date around it.
For a quick cost check, an address billed at $0.005 per hour costs about $44 a year. Multiply that by your address count and holding period, then compare it with the full cost of buying.
Choosing a Block Size and Region
Smaller blocks, especially /24s, usually cost more per address because more buyers want them. Larger blocks can cost less per address but tie up more capital and can be harder to resell. In registries that require needs justification, you also have to support the size you request.
Start with the registry that serves your network and where your organization holds, or can open, an eligible account. Transfers between registries are possible where policies are compatible, but they add a second set of requirements. Teams building out a computer networking business often find an in-region transfer simpler for a first purchase.
Holding rules matter if plans change. RIPE NCC generally applies a 24-month restriction before received IPv4 space can be transferred again, so confirm the rules before assuming a quick resale.
How Each Registry Handles Transfers
The basic flow is the same everywhere. The buyer establishes eligibility, the seller proves its authority and the registry reviews the transfer before updating its records.
| Registry | Key transfer points |
| ARIN | Optional pre-approval of need; /24 minimum for in-region (8.3) and inter-RIR (8.4) transfers |
| RIPE NCC | Buyer needs the right membership or sponsoring arrangement; 24-month holding period on received space |
| APNIC | Both parties generally need APNIC accounts; recipient pays a transfer fee before the record is updated; pre-approval valid for 24 months |
| LACNIC | /24 minimum; recipient must justify need; public transfer log |
Inter-registry transfers need compatible policies on both sides. The receiving registry checks the buyer, the source registry checks the seller and one approval alone doesn’t complete the deal.
The Buyer’s Due Diligence Checklist
A listing or broker report is a useful start, but it doesn’t replace your own checks. Work through these four areas before any money moves.
Registry record and authority
Look up the block in the relevant registry’s database. Confirm the seller matches the registered organization or can document its authority to act for it. Resolve former names, subsidiaries and acquisition history first, and ask the registry to confirm the block is eligible to transfer.
Routing records (IRR and RPKI)
Internet Routing Registries (IRRs) hold route objects that tie a prefix to a network’s autonomous system number. Resource Public Key Infrastructure (RPKI) supports Route Origin Authorizations (ROAs), signed records that say which network may announce a prefix.
If the only valid ROA still names the seller’s network, your announcement could be rejected as invalid. Agree up front who removes old records, who creates new ones and when.
Reputation
Check the block against the blocklists that matter for your use. Spamhaus, for example, offers a lookup and removal process. A listing isn’t always a deal-breaker, but removal takes time and isn’t guaranteed.
Geolocation and paperwork
Commercial databases may still place the block in the seller’s country. After transfer, publish a geofeed and submit corrections to providers such as MaxMind, knowing updates can take time.
On paperwork, agree on escrow or staged payment tied to registry confirmation. Arrange any letter of authorization (LOA) your provider needs, and settle who controls reverse DNS.
Where to Buy Global IPv4
The right channel depends on how much price certainty and support you want. None of them replaces registry approval or your own technical checks.
| Channel | How pricing works | What you typically get | Watch for |
| Auction marketplace | Competitive bidding | Price discovery | Uncertain final price and deadlines |
| Private broker | Negotiated | Sourcing and paperwork help | Commission structure |
| Fixed-price marketplace | Listed price | Clear asking price and transfer support | Inventory and scope of services |
| Direct counterparty | Negotiated | No commission | You handle diligence and registry work |
Fixed-price marketplaces such as IPv4 Connect list blocks at published prices and include a free blacklist report with every subnet. The team also manages transfers in the ARIN, RIPE and APNIC regions, including clearing old BGP announcements and route records before handover.
Whichever channel you use, ask the same questions. What triggers payment release, which reputation checks are included and who handles routing cleanup after approval?
What It Really Costs
IPv4 prices vary by block size, registry and supply, so a large-block sale is a poor guide to /24 pricing. Compare completed sales with asking prices from more than one source, and check whether fees are included.
The address price is only part of the budget. Add registry charges, marketplace or broker fees, escrow and engineering time. For cloud deployments, confirm BYOIP eligibility before counting on any savings.
Don’t rely on a future resale price to justify a purchase you couldn’t otherwise afford. Unused capacity and ongoing administration can quietly erode the savings.
After the Transfer
Registry records, provider filters and third-party databases update at different speeds. Prepare the technical work early, then complete it in order.
- Confirm registration. Check the registry record shows your organization and save the confirmation.
- Set routing authorization. Create ROAs for your origin network and confirm old seller ROAs are gone.
- Update route objects. Create or update IRR entries and give providers time to refresh filters.
- Announce the block. Supply any LOA, confirm provider acceptance and check reachability with RPKI validation tools.
- Configure reverse DNS. Publish PTR records before mail or other services depend on them.
- Fix geolocation. Publish your geofeed and submit corrections.
- Verify readiness. Recheck blocklists, test your services and ramp up mail volume gradually.
Final Thoughts
Before buying, answer three questions. Will long-term control justify the total cost, can you meet the registry’s eligibility rules and can your team manage the handover?
If the answer is yes, verify the seller’s authority, routing records and reputation before paying. Then put every handover responsibility in writing.
FAQ
Can my business buy IPv4 in any region?
You generally buy through the registry that serves your network and where you hold, or can open, an eligible account. Inter-registry transfers are possible where policies are compatible, but they add extra requirements.
What is the smallest block worth buying?
A /24 with 256 addresses. Smaller blocks are commonly filtered from the global routing table.
How long does an IPv4 transfer take?
It depends on registry review, documentation and payment. Getting pre-approval where the registry offers it can remove much of the delay.
Is buying cheaper than leasing?
It can be for steady, long-term demand. For short projects or uncertain needs, leasing or provider-assigned addresses often cost less overall.
What happens if the block is on a blocklist?
You can request removal, but it takes time and isn’t guaranteed. Check reputation before paying rather than after.
