Buy IPv4 Addresses: A Complete Guide for Network Pros

Overview: Why buy IPv4 addresses now?

IPv6 has advanced, but IPv4 still matters for legacy gear, CDN footprints, geo-targeted services and many third‑party integrations. For a lot of ISPs, hosting providers and enterprises, buying or leasing IPv4 is the quickest practical way to get publicly routable addresses. A carefully handled purchase prevents routing surprises, regulatory headaches and throwing money at short-term hacks like complex NAT overlays.

How the IPv4 market works

The secondary IPv4 market links sellers — typically ISPs or enterprises — with buyers such as hosting providers, cloud operators and other companies. Brokers and online marketplaces facilitate most deals. You’ll see either permanent transfers (registered with the Regional Internet Registry, or RIR) or time-limited leases; the choice affects cost and operational responsibility.

• Common sale units: /24 retail units; larger blocks (e.g., /20, /16) trade at lower per-IP cost.
• Transaction methods: direct sale, brokered sale, or lease.
• Marketplace services: escrow, transfer assistance, and seller verification reduce risk.

Good marketplaces also keep paperwork organized and offer post-transfer support. IP4 Market is mentioned here as an example of a platform that lists verified sellers and aims to simplify compliance and registration.

Step-by-step buying process

1. Define requirements

Work out how many addresses you need now and over the next planning cycle. Decide if you require contiguous space (helps with route aggregation and simpler ACLs) and whether permanent ownership or a lease better fits your strategy. Also plan ASN and peering: announcing new space needs upstream coordination, so don’t leave that until the last minute.

2. Confirm RIR policy & eligibility

Each RIR (ARIN, RIPE NCC, APNIC, LACNIC, AFRINIC) has its own transfer rules and documentation requirements. Check eligibility early — missing paperwork is one of the most common causes of delays.

3. Source and evaluate offers

Tap several channels: trusted marketplaces, experienced brokers and industry contacts. Look beyond price: evaluate seller reputation, block provenance and whether transfer assistance is included. Features like escrow and seller verification materially lower transactional risk.

4. Conduct technical and legal due diligence

• Verify route history and origin AS with tools such as RIPEstat, BGP.he.net and public looking glasses.
• Check block blacklists and abuse history against common spam/abuse databases.
• Confirm there are no active disputes or pending RIR actions on the block.
• Obtain seller proof of control (billing records, RPKI attestations or upstream confirmations).

5. Negotiate and document the deal

Agree the total landed cost: per-IP price plus escrow, broker and RIR fees, and any seller assistance. For leases, be explicit about duration, SLAs and rollback procedures. Insist on a written sale or lease agreement that spells out transfer mechanics and who is responsible for each step.

6. Complete the RIR transfer

Submit the transfer request according to the RIR’s procedure and attach the required documents. Many brokers and marketplaces will manage this to reduce errors and speed registration. Timing varies — from a few days to several weeks — depending on how complete the paperwork is and the RIR’s current workload.

7. Post-transfer configuration and monitoring

• Register the block in your RIR account and update whois contact details.
• Publish RPKI ROAs and align routing policies with your upstreams.
• Watch BGP propagation, routing filters and any abuse reports for the newly acquired space.
• Keep all transfer documentation and receipts for compliance and possible future audits.

RIR transfer rules — quick comparison

Rules and processes vary by region. The brief table below highlights key differences to help with pre‑purchase planning; always refer to the RIR’s official policy pages for the final word.

Valuation & pricing considerations

Price depends on block size, region, supply and how straightforward the transfer is. When comparing offers, calculate the total landed cost: quoted price plus escrow, broker fees, RIR charges and any legal work.

• Per-IP pricing: larger contiguous blocks usually mean a lower per-IP rate.
• /24 blocks are the common retail unit and often carry a per-IP premium versus bulk buys.
• Leases: recurring payments (monthly/annual) at a fraction of purchase price; they suit short-term needs.

Practical tips for a smooth purchase

• Use escrow and documented transfer processes to protect funds and ensure seller obligations are met.
• Confirm upstream/provider acceptance of the block before completing purchase if you need to announce it immediately.
• Request RPKI ROAs or other cryptographic proof of control from the seller when available.
• Retain all sale and transfer communications and invoices for future audits or dispute resolution.
• Consider working with an experienced broker for a first-time purchase to avoid operational mistakes.