Every Regional Internet Registry (RIR) has exhausted its free pool of IPv4 addresses. If your business needs new IPv4 space today — for hosting, a growing ISP, a SaaS platform or a new data center — the practical route is to buy IPv4 addresses on the transfer market from an organization that no longer needs them.
Buying IPv4 is not like buying a domain name. The addresses must be formally re-registered to you by the relevant RIR, and a block's history can affect how useful it is. This guide walks through the process step by step so you know what to expect and what to check.
Step 1: Work out how many addresses you need
Start by sizing your requirement in CIDR notation. A /24 contains 256 addresses and is the smallest prefix generally accepted in the global BGP routing table, so it is the minimum most businesses buy for public use. Each step up doubles the size: a /23 is 512 addresses, a /22 is 1,024 and so on.
Plan for at least 12–24 months of growth. Buying one larger block is usually simpler to route and manage than several small ones. Our free IPv4 subnet calculator shows the address count, usable hosts and masks for any prefix.
Step 2: Know which registry you will use
IPv4 space is registered with one of five RIRs: ARIN (North America), RIPE NCC (Europe, the Middle East and Central Asia), APNIC (Asia Pacific), LACNIC (Latin America and the Caribbean) and AFRINIC (Africa). You normally need an account (membership) with the RIR that will hold your registration.
Each registry has its own transfer policy. Some require the buyer to document a need for the addresses before the transfer is approved; some apply holding periods after a transfer; and inter-RIR transfers are only possible between registries whose policies allow them. A good broker will check the current policy for your specific case before you commit.
Step 3: Source a block and check its reputation
Once you know the size and registry, a broker can match you with available inventory. Before agreeing a price, the block should be checked for:
- Blacklist history — listings on major spam and abuse databases can cause email delivery and access problems.
- Routing history — previous announcements, hijack reports or unusual BGP activity.
- Geolocation data — where geo-IP databases currently place the block, which can affect streaming, banking and ad services for your users.
- Clean registration — the seller must be the verified registrant with the right to transfer the block.
Step 4: Agree terms and sign the transfer agreement
Price per address depends on block size, registry, reputation and market conditions (see our guide on what drives IPv4 prices). Once terms are agreed, buyer and seller sign a written transfer agreement that covers the block, price, payment timing and each party's obligations.
Payment is usually structured so that funds are only released to the seller after the registry has confirmed the transfer, protecting both sides.
Step 5: Complete the RIR transfer
The transfer request is submitted to the registry with the supporting documents. The RIR reviews ownership, policy compliance and — where required — the buyer's justification. Timelines vary by registry and by how complete the paperwork is; many purchases complete within one to four weeks.
When the registry updates the record, the block is registered to your organization. You can then create route objects and RPKI ROAs and announce the prefix from your ASN.
Common mistakes to avoid
- Buying the smallest possible block and running out within months.
- Skipping reputation checks to save time — cleaning up a listed block later is slow.
- Paying before the registry transfer is confirmed.
- Not checking whether your registry requires needs justification before you sign.
Buy IPv4 with an experienced broker
All Tech Cloud Services has helped businesses across 50+ countries buy clean IPv4 space since 2019, handling due diligence, agreements and the RIR transfer end-to-end. Request IPv4 inventory and a specialist will reply within 24 hours.
Frequently asked questions
Most buyers start with a /24 (256 addresses) because it is the smallest prefix generally accepted in global BGP routing. Smaller blocks are hard to use on the public internet.
Many purchases complete in one to four weeks, depending on block availability, how quickly the agreement is signed and the registry's processing time.
In most cases the buyer needs an account with the registry that will hold the registration. Your broker can confirm the requirements for your region.