Your CFO just flagged the new AWS public IPv4 charges. Deliverability slipped after a shared IP problem last quarter. Engineering needs portable addresses for a multi-cloud rollout. This mix of finance, marketing, and infrastructure pressure is now common.
ARIN, the American Registry for Internet Numbers, exhausted its free IPv4 pool in September 2015. Since then, organizations have relied on transfers, special reserves, or a waitlist to get more address space.
AWS then began charging $0.005 per public IPv4 address per hour in February 2024. What used to feel free is now a visible operating cost.
Owning the right block can cut recurring cloud fees, steady sender reputation and reduce vendor lock-in. It only works if the space is clean, the transfer is valid, and routing is protected with Resource Public Key Infrastructure (RPKI).
Use this article as an operations checklist for pricing, vetting, transfer steps, and deciding when leasing makes more sense than buying.
Key Takeaways
Here are a few rules that drive most good IPv4 decisions:
- You’re buying registration rights, not property. Escrow should release only after the registry record updates.
- The smallest practical block is a /24. Smaller announcements are filtered by many networks.
- Price is only part of the deal. Clean reputation and clear ownership history justify higher pricing.
- ARIN recipients must justify 24-month need. Pre-approval speeds closing, but documentation must be ready.
- Bring Your Own IP (BYOIP) can cut AWS public IPv4 costs. It also improves portability across clouds.
- Most risk lives in reputation and routing. Check blocklists, routing history, and publish ROAs on day one.
- For email, a clean dedicated /24 plus careful warm-up supports inbox placement. Shared reputation is harder to control.
What You’re Actually Buying
When teams say they want to buy IPv4, they mean they want the right to be recorded as the holder of a prefix in a regional internet registry (RIR). In the ARIN region, those rights are governed by the Registration Services Agreement.
That difference matters in contracts. Your escrow release should depend on the registry and WHOIS update, not on an invoice or a seller promise. If the registry never changes, you do not control routable space.
You will also hear about legacy space and RSA-covered space. Legacy blocks predate current ARIN agreements, so chain-of-custody records, historic WHOIS data, and proof of corporate authority matter even more.
One more rule shapes almost every purchase. A /24, or 256 IPv4 addresses, is the smallest widely routable announcement on the public Internet. More specific prefixes are filtered by many networks, so buying less can create real reachability gaps.
Why Growth Teams Choose To Own IPv4
Owning IPv4 solves cost, reputation, and portability problems at the same time. This makes it as much a financial decision as it is a network decision.
1. Cost Control Against Cloud IPv4 Fees
BYOIP can remove AWS charges for Amazon-provided public IPv4 addresses. At $0.005 per hour, 256 public IPs cost about $934 a month, or roughly $11,200 a year.
A /24 bought in the low-$30s per IP range, plus ARIN fees, escrow, and closing costs, usually lands near $9,500 to $10,000 in year one. After that, ongoing cost is mostly ARIN’s annual registration fee, around $262.50 for a /24.
If you need only a few dozen addresses, leasing or cloud-assigned space may still be cheaper.
2. Deliverability and Brand Trust
Dedicated space gives you control over sender reputation. That matters more after Gmail’s February 2024 sender rules, which tightened requirements for authentication and complaint handling.
For bulk email, you need SPF, DKIM, and DMARC, the core authentication records, plus a clean IP history. A fresh block is not a shortcut. Warm it up slowly, increase volume over two to three weeks, seed-test, and watch Gmail Postmaster Tools for complaints and spam placement.
3. Multi-Cloud Portability and Resilience
Provider-assigned IPs tie your service to one platform. Owned space gives you a stable address range you can carry across AWS, Azure, and Cloudflare.
That portability helps during migrations and outages. If you need to move traffic quickly, you avoid changing customer allowlists, firewall rules, and every internal document that references those addresses.
What a /24 Costs in 2026
Market pricing has softened, but block quality still drives the spread.
By late 2025 to early 2026, many transfers were clearing in the low-$30s per IP for smaller blocks, while some large /16 blocks dipped below $20 per IP. That headline number is useful, but it is never the whole story.
For a /24 at $32 per IP, the base price is $8,192. Add ARIN’s $500 transfer processing fee, the $187.50 recipient fee, escrow, and any broker charges, and year-one total commonly lands near $9,500 to $10,000.
Leasing still has a place. IPXO market data in 2025 to 2026 showed average lease rates around $0.40 per IP per month, which can beat ownership for short projects, temporary overages, or uncertain demand.
- ARIN transfer processing fee: $500
- ARIN recipient fee for a /24: $187.50
- Typical /24 clearing price: low-$30s per IP
- Lease benchmark: about $0.35 to $0.45 per IP per month
- AWS public IPv4 charge: $0.005 per IP per hour
- Minimum ARIN transfer size: /24
How to Vet a Block
The biggest buying risk is not overpaying, it is ending up with dirty or disputed space.
Start with reputation
Check Spamhaus SBL, the Spamhaus Block List, and DROP, the list of netblocks that should not be routed. Then review other major blocklists and ask for any recent delisting history. A seller who cannot explain past listings is handing you cleanup work.
Verify chain of custody
Match the seller’s Org handle, old WHOIS records, company name, and signing authority. If the block changed hands through a merger or asset sale, ask for documentation that shows that transfer path clearly.
Review routing history
Look for suspicious origin changes, unexplained gaps, or signs of hijacking. Check route objects in the Internet Routing Registry, or IRR, so you know what must be removed or updated after close.
Confirm RPKI readiness before you fund anything
After transfer, you should publish Route Origin Authorizations (ROAs), immediately to reduce the chance of unauthorized BGP announcements.
Geolocation is the quieter problem. Submit location corrections to MaxMind after transfer and expect lag before databases catch up. If country accuracy affects licensing, taxes, or fraud controls, plan that work in advance.
Direct deals look cheaper on paper, yet they carry the most chain-of-custody risk. Always use escrow, insist on ARIN pre-approval, and verify that the signer has authority to sell the space.
Finally, make sure your 24-month ARIN need statement is solid. Capacity plans, utilization logs, and growth assumptions should be ready before you open the ticket.
How to Source IPv4
The way you source a block affects speed, price, and fraud exposure.
In practice, a vetted broker can reduce risk by checking chain of custody, recent routing history, Spamhaus status, and escrow timing before funds move, while also helping buyers organize ARIN 8.3 paperwork and basic closing steps. If you are in the ARIN region and want a cleaner process, that support can help teams move faster when they need to buy IP addresses without derailing a launch timeline.
Marketplaces and brokers usually cost more than a direct private deal, but they can reduce avoidable mistakes. Visible pricing also helps you judge whether an asking price matches the current market.
Watch for obvious red flags, including pressure to skip escrow, refusal to run SBL or DROP checks, vague Letters of Authorization, or a seller who wants funds released before ARIN updates the registry.
If your team has never handled ARIN paperwork, a specialist can be worth the fee because the hard part is not finding a prefix, it is closing cleanly. Teams in the ARIN region sometimes use specialist help to pre-screen subnets against Spamhaus lists, coordinate ARIN 8.3 paperwork, and line up escrow so a purchase does not stall just before launch.
How ARIN Transfers Work
Pre-approval, escrow, and a registry update are the steps that keep the deal both safe and fast.
ARIN Number Resource Policy Manual section 8.3 covers specified transfers inside the ARIN region, while section 8.4 covers inter-RIR transfers. The workflow is simple, but every document needs to line up.
- Get pre-approval. Submit your 24-month justification, utilization data, and growth documentation.
- Sign a letter of intent. Add contingencies for escrow, reputation checks, and ARIN approval.
- Fund escrow. Use a neutral third party and tie release to the registry update.
- Open the ARIN ticket. Source and recipient submit the required transfer materials.
- Wait for approval and WHOIS update. ARIN reviews the request and updates the record.
- Finish technical setup. Publish ROAs, update IRR objects, set reverse DNS, and prepare BYOIP onboarding.
With pre-approval in place, review often takes one to three weeks. Without it, missing utilization data or weak corporate records can add days or weeks.
How BYOIP Works on AWS, Azure, and Cloudflare
Once the registry shows you as the holder, major platforms can announce your own space.
Bring Your Own IP (BYOIP), lets you advertise your registered prefix from a cloud or edge provider instead of using provider-assigned addresses.
AWS: VPC IP Address Manager supports BYOIP for ranges registered with an internet registry. The per-hour public IPv4 charge applies to Amazon-provided IPs, not to your BYOIP space.
Cloudflare: Cloudflare can announce customer-owned prefixes across its edge network. Publish your ROAs before onboarding so valid announcements are less likely to run into routing policy issues.
Azure: Custom IP Prefix supports BYOIP with its own provisioning flow. Review load balancer and public IP attachment details before you commit traffic.
Write runbooks for announcement, testing, rollback, and failover. The worst time to discover a provider quirk is during an outage.
What to Do in the First 30 Days After Acquisition
The first month determines whether your new block becomes an asset or a cleanup project.
Start with routing security. Create ROAs with tight maxLength values, validate propagation, and enable route-origin validation with upstreams where available.
Next, set reverse DNS, or rDNS, for every mail and application host. Use stable hostnames that match how the systems will actually appear in logs and headers.
If the block will send email, warm it up slowly. Begin with engaged traffic, watch bounces and complaint rates every day, and do not dump full campaign volume onto fresh space.
Submit geolocation corrections early. MaxMind and similar databases do not update instantly, and stale country data can confuse fraud rules, analytics, and customer support.
Monitor route propagation, latency, SMTP performance, and blocklist status for at least 30 days. Keep access tight as well, because address delegation mistakes are hard to unwind once partners start allowlisting your range.
How to Balance IPv4 and IPv6
IPv6 is growing fast, but it has not removed the need to manage IPv4 well.
Google’s measurements showed native IPv6 user access briefly topping 50% in March 2026. That shift is real, yet dual-stack operations will remain normal for years.
Treat IPv4 as a scarce operational asset. Own a core /24 or /23 for reputation-sensitive traffic, lease short-term space for bursts, and enable IPv6 everywhere your stack supports it.
If someone argues that IPv6 makes IPv4 buying pointless, look at partner allowlists, legacy SaaS integrations, and email infrastructure. These dependencies still lean heavily on IPv4.
FAQ
These are the questions that usually slow a purchase down.
How Much Does a /24 Cost Right Now?
Late 2025 to early 2026 market data showed many /24 blocks clearing in the low-$30s per IP. Clean blocks with no blocklist history usually command a premium.
What Are ARIN Transfer Fees and Who Pays?
ARIN charges a non-refundable $500 transfer processing fee per request. The recipient also pays a size-based fee, and for a /24 that fee is $187.50 in most deals.
What’s the Minimum I Can Buy and Still Route Globally?
A /24, which is 256 addresses, is the minimum transfer size in ARIN and the smallest prefix widely accepted across the global routing table.
How Long Does an ARIN Transfer Take?
With pre-approval in place, many transfers close in two to four weeks. Weak documentation or missing utilization data can stretch that timeline.
Are IP Addresses Property?
No. In ARIN, you receive service-based registration rights under the Registration Services Agreement, not traditional property ownership.
Can I Use My Own IPs on AWS, Azure, and Cloudflare?
Yes. All three support BYOIP workflows, but each has its own onboarding steps, validation checks, and service attachment rules.