A Practical Guide to Buying IPv4 Addresses for Business Growth
I watched a network team spend six weeks chasing a single /24 after a launch stalled on address space. They had a budget, approval, and a deployment window. They lacked routable IPv4.
That is becoming normal.
The IANA IPv4 free pool was exhausted on February 3, 2011. ARIN’s general pool ran dry in September 2015, and RIPE NCC announced exhaustion on November 25, 2019. AWS then began charging $0.005 per hour for every public IPv4 address, which turned address use into a clear line item.
IPv6 is growing. Google’s measurements briefly showed IPv6 traffic surpassing 50% worldwide on March 28, 2026. But most businesses still run dual-stack networks, which means running IPv4 and IPv6 together, so routable IPv4 still matters.
The job is simple to define and hard to execute: size the purchase, vet the block, finish the transfer, and make the space usable on day one.
Key Takeaways
You can still get IPv4, but only through transfers and disciplined operations.
- Fresh IPv4 supply is gone at every regional internet registry, or RIR. Most buyers use transfers. Start with a /24, then grow into larger blocks.
- Diligence prevents outages. Check legal ownership, blocklists, routing history, registry records, and route authorizations before you announce.
- Match the channel to your risk tolerance. Brokers reduce compliance work, marketplaces improve price discovery, and direct deals fit targeted acquisitions.
- Policy varies by region. ARIN uses recipient pre-approval for 24-month needs, RIPE applies a re-transfer hold period, and APNIC allows /24-minimum transfers.
- Pricing moves in cycles. Large-block prices fell from highs in the $50s per IP in early 2024 to around $20 at points in 2025.
- Buying IPv4 buys time, not a replacement for IPv6. Use it to support growth while you keep rolling out dual-stack services.
What the IPv4 Shortage Means
No registry can hand out large new IPv4 pools anymore, so growth depends on the transfer market.
IPv4 has about 4.3 billion addresses. The last five /8 blocks left the central IANA pool in 2011, and the RIRs exhausted their general pools after that. APNIC reached its Final /8 stage on April 15, 2011; ARIN ran out in 2015, and RIPE followed in 2019.
A few terms matter here. RIR means regional internet registry. IRR is the Internet Routing Registry used by filters to check route data. ROA is a signed record that authorizes an origin AS, or autonomous system, to announce a prefix. CGNAT means carrier-grade NAT, which shares one public address across many users.
Businesses still need IPv4 for partner allowlists, which approve traffic from specific IPs, plus mail reputation, stable geolocation, firewalls, and third-party tools that remain IPv4-only. CGNAT saves addresses, but it complicates logging and inbound access.
Three Benefits of Buying IPv4
Owned address space gives you control that shared or short-term space rarely matches.
The benefits are operational. A clean block removes bottlenecks that slow launches, mail programs, and partner onboarding.
Control and Reachability
Owned, routable space supports inbound services, stable geolocation, and a cleaner sender reputation. Border Gateway Protocol, or BGP, lets you choose how traffic enters and leaves your network instead of accepting a provider’s defaults.
Faster Growth Operations
Mergers, new regions, partner VPNs, and SaaS migrations all need address headroom. A clean /24 can unblock allowlists, peering, and tenant setup without a rushed renumbering project.
Residual Value and Flexibility
IPv4 still has resale value and can be subdivided with care. It does not replace IPv6, but it remains useful when you document ownership, fair value, and routing hygiene for audits.
What to Buy So Your Blocks Work on Day One
The right block is clean, routable, and ready for reputation-sensitive traffic.
For most buyers, a /24 is the practical minimum. Internet routers usually filter anything longer than /24, so smaller prefixes may not propagate globally. ARIN and APNIC also set /24 as the minimum transfer size.
Clean versus dirty space. Ask for blocklist scans and recent BGP history. Avoid netblocks with active abuse complaints, hijack disputes, or persistent geolocation errors.
Routing readiness. Set IRR route objects and create Resource Public Key Infrastructure, or RPKI, ROAs before you announce. As of Q1 2026, about 65.5% of global IPv4 space was RPKI-valid, so many upstreams already enforce origin checks.
Email readiness. If you send mail at scale, warm new IPs slowly, and match PTR, SPF, DKIM, and DMARC records. PTR is the reverse DNS record that maps an address back to a hostname. Reverse DNS lives under in-addr. arpa, so plan that handoff with the RIR as soon as the transfer closes.
Geolocation. Publish an RFC 8805 geofeed, which is a file that tells providers where your IPs are used, and submit corrections to MaxMind and IPinfo right after transfer.
A 10-Point Due-Diligence Checklist
A short diligence process now is cheaper than an outage or deliverability mess later.
- Verify current RIR WHOIS data, OrgID, and legacy status.
- Use escrow and match signers to RIR contacts.
- Confirm transfer minimums and any regional hold periods.
- Review BGP history for leaks or suspicious AS paths.
- Confirm IRR objects can be updated or replaced cleanly.
- Draft ROAs with the right origin AS and maxLength.
- Run blocklist checks and require seller cleanup if listed.
- Check geolocation databases and draft correction requests.
- Prepare letters of authorization if providers need them.
- Document cutover steps, freeze windows, and validation tests.
Where to Buy So You Don’t Get Burned
Your sourcing channel affects price, speed, and the amount of risk your team carries.
Three paths dominate the market, and each creates a different workload.
Brokers. Full-service help usually includes compliance support, vetted inventory, escrow coordination, and inter-RIR experience. Fees are the tradeoff. This path fits first-time buyers and regulated teams.
Marketplaces and Auctions. They give you faster price discovery, but your team handles most diligence. They work best when you already have network, legal, and finance support in-house.
Direct Corporate Sellers. These deals can fit M&A plans or geography targets, but supply is thin, and negotiations usually take longer.
Whatever channel you use, align recipient accounts and pre-approvals before you bid. ARIN’s 8.3 and 8.4 paths allow recipient pre-approval based on 24-month projected need. RIPE’s re-transfer hold period can limit future flexibility, so build that into your timeline.
For teams that want a vetted, managed path through sourcing, compliance, and post-transfer routing, buy IP addresses through Brander Group, which brings over 20 years of experience, 2,500 global clients across 60 countries, and 50 to 70 completed IPv4 transfers per month in ARIN, RIPE, and APNIC. The firm is recognised by both Fortune Magazine and the Financial Times and handles everything from blacklist screening and pre-approval through to final WHOIS update.
How to Execute the Transfer
Transfers move faster when legal, registry, and routing work happen in parallel.
Phase 1, Internal Prep, Week 0-1. Quantify 24-month need, confirm your recipient account at the right RIR, and secure budget for the block, escrow, and registry fees.
Phase 2, Deal and Escrow, Week 1-3. Negotiate price, prefix size, seller warranties, and remediation for reputation or RPKI issues. Fund escrow and exchange transfer templates.
Phase 3, RIR Processing, Days 3-15. Both parties submit transfer requests and answer registry tickets quickly. After approval, confirm WHOIS changes and reverse-DNS delegation.
Phase 4, Make It Routable, Day 0. Publish ROAs and IRR objects, provide letters of authorization to upstreams if required, and verify global propagation with looking glasses.
Phase 5, Make It Usable, Day 0-7. Set PTRs, update allowlists, publish your geofeed, monitor route validity and blocklists, and record ownership in your CMDB, or configuration management database.
How to Track Success
Good IPv4 operations are measurable, so define success before the transfer closes.
Routing KPIs. Track the share of prefixes that are RPKI-valid, time to first propagation across major transit networks, and zero invalid announcements.
Security and Reputation. Measure IRR-to-ROA parity, critical blocklist appearances, abuse ticket response time, and SPF, DKIM, and DMARC pass rates.
Financial and Operational. Calculate cost per routable IP online, avoid cloud IPv4 fees, time from purchase order to production, and fewer geolocation or VPN issues.
Make IPv4 Work for You, Not Against You
Treat purchased IPv4 as a bridge that supports growth while IPv6 catches up.
Buying IPv4 should reduce risk, not delay your IPv6 plan. Use the space to support launches, partner access, and stable mail reputation while you keep dual-stack adoption moving.
Three habits prevent most post-purchase failures: publish geofeeds, keep ROAs and IRR records in sync, and review reputation data each quarter.
FAQ
Most buying questions come down to legality, size, timing, and whether ownership really pays off.
Is Buying IPv4 Legal?
Yes. Transfers are governed by RIR policy. Use escrow, complete the registry process, and verify that the seller controls the resources before money moves.
What’s the Smallest Block You Should Buy?
A /24, or 256 addresses, is the practical minimum for global reach. Smaller prefixes are usually filtered by transit networks, and several regions also use /24 as the minimum transfer size.
How Long Does a Transfer Take?
With pre-approval and clean paperwork, an intra-RIR deal can close in days. Inter-RIR transfers usually take longer because they add coordination and policy checks.
Should You Lease Instead of Buy?
Lease if demand is short-term or volatile. Buy if you need long-term control, reputational isolation, or a predictable total cost of ownership. Model both options against cloud IPv4 fees before deciding.
Do You Still Need IPv6?
Yes. Buying IPv4 gives you runway, not an endpoint. New services should launch dual-stack where possible, and your IPv6 rollout should continue in parallel.
