Businesses can add servers in hours, increase cloud capacity almost instantly, and purchase more bandwidth as demand grows.
Public IPv4 addresses are different.
IPv4 has a finite address space, and the pools of previously unallocated addresses available through the Regional Internet Registry system have been exhausted or significantly constrained.
For network operators, this creates a practical challenge:
What happens when you need to buy IP addresses but the amount of available IPv4 is limited?
Internet service providers, hosting companies, data centers, cloud platforms, SaaS businesses, telecom operators, and enterprises may still require public IPv4 for expanding infrastructure.
But buyers can no longer assume that any prefix size, registry region, or quantity will always be immediately available.
Understanding how IPv4 supply works—and how an IPv4 marketplace helps match available resources with buyers—is therefore an important part of modern network planning.
Why Is IPv4 Supply Limited?
IPv4 uses a 32-bit address space.
That provides roughly 4.3 billion possible addresses, with part of that space reserved for special purposes rather than ordinary public Internet use.
During the Internet’s early development, that seemed enormous.
It was not.
As Internet access expanded globally, organizations consumed the available pool of IPv4 resources.
Regional Internet Registries eventually reached exhaustion of their general pools of readily allocatable IPv4 address space.
That does not mean IPv4 has disappeared.
Billions of addresses are still actively used.
Instead, exhaustion means organizations that need additional IPv4 increasingly depend on resources that have already been allocated.
Those resources may become available through:
- IPv4 transfers
- Existing organizational holdings
- IPv4 marketplaces
- Leasing
- Returned or recovered address space
- Network restructuring
This has transformed IPv4 procurement.
The question is no longer simply:
“Can we request more IPv4?”
It is increasingly:
“Where can we find suitable IPv4 that another organization can make available?”
Why Businesses Still Buy IPv4 Addresses
IPv6 provides a vastly larger address space and should remain part of long-term network planning.
However, IPv4 connectivity continues to matter for many real-world environments.
Organizations may need IPv4 for:
- Dedicated servers
- Cloud infrastructure
- Hosting customers
- ISP networks
- Public APIs
- VPN gateways
- Enterprise systems
- SaaS services
- Security appliances
- Data center infrastructure
- Customer-facing applications
For businesses expecting to use the addresses over a long period, purchasing IPv4 can provide strategic capacity.
That is why searches for buy IP addresses remain commercially relevant even as IPv6 adoption continues.
Where Does IPv4 for Sale Come From?
Since new IPv4 supply is constrained, much of the address space available for purchase comes from organizations that already hold it.
A company may decide to make IPv4 available after:
- Migrating services to the cloud
- Consolidating data centers
- Deploying IPv6
- Restructuring networks
- Completing a merger
- Closing legacy services
- Improving address utilization
- Reducing public IPv4 requirements
That creates a secondary market.
One organization has more IPv4 than it needs.
Another needs more IPv4 than it currently has.
An IPv4 marketplace helps bring those two sides together.
Is There Still IPv4 Available to Buy?
Yes, but availability should not be interpreted in the same way as inventory for a conventional product.
There is no factory producing additional IPv4 blocks.
Marketplace supply depends on resource holders deciding to make existing address space available.
This means IPv4 availability can vary according to:
- Prefix size
- RIR region
- Seller activity
- Transfer eligibility
- Address history
- Buyer demand
- Market conditions
A buyer looking for a /24 may encounter a very different market from an organization seeking a /16.
Availability also changes over time.
A block visible today may be purchased by another buyer tomorrow, while a new seller may later bring additional resources into the market.
Businesses should therefore treat IPv4 sourcing as a procurement process rather than expecting unlimited permanent inventory.
How Prefix Size Affects IPv4 Availability
One of the first things buyers should understand is CIDR block size.
Common IPv4 prefixes include:
| Prefix | Total IPv4 Addresses |
|---|---|
| /24 | 256 |
| /23 | 512 |
| /22 | 1,024 |
| /21 | 2,048 |
| /20 | 4,096 |
| /19 | 8,192 |
| /18 | 16,384 |
| /17 | 32,768 |
| /16 | 65,536 |
A buyer who needs 256 addresses has a different sourcing problem from one that needs 65,536.
Large contiguous blocks can be particularly important for organizations that want simplified routing or significant long-term capacity.
Buyers should therefore define their required prefix size before entering the market.
Don’t Wait Until Your IPv4 Pool Is Full
One of the biggest IPv4 procurement mistakes is waiting until existing capacity is almost completely consumed.
Suppose a hosting provider expects to exhaust its available IPv4 within six months.
If it begins sourcing only when the last few addresses remain, it creates unnecessary pressure.
The business may then be forced to compromise on:
- Block size
- Registry region
- Price
- Address history
- Transaction timing
A better approach is to incorporate IPv4 into network capacity forecasting.
Track:
- Current utilization
- Monthly address consumption
- Expected customer growth
- Server deployments
- Geographic expansion
- Reserved capacity
- IPv6 migration
This allows procurement teams to enter the IPv4 marketplace before address scarcity becomes an emergency.
How Much IPv4 Should You Buy?
Buying exactly enough IPv4 for today’s network may not be sufficient.
For example, imagine an ISP currently requires 3,000 additional addresses.
A /20 provides 4,096 addresses.
That may solve the immediate requirement.
But if the network expects to add several thousand customers shortly afterward, the operator may soon need another acquisition.
Businesses should therefore evaluate:
Current demand + expected growth + reasonable reserve capacity.
At the same time, buying dramatically more IPv4 than needed can tie up capital.
The correct balance depends on the organization’s growth outlook.
IPv4 Availability Is About More Than Quantity
Finding enough IPv4 addresses is only one part of supply.
Buyers also need to find the right address space.
A technically available block may still be unsuitable for a particular organization.
Several factors should be evaluated.
1. Regional Internet Registry
IPv4 resources are administered through five Regional Internet Registries:
- ARIN
- RIPE NCC
- APNIC
- LACNIC
- AFRINIC
The registry associated with a block affects the transfer process.
Buyers should determine whether they need resources within a particular RIR or whether an inter-RIR transaction may be possible.
This can significantly change the pool of potential resources.
2. Transfer Eligibility
A block being advertised for sale does not automatically mean that a transfer can proceed immediately.
The seller and resource may need to satisfy requirements under the applicable registry policy.
Buyers should verify this early.
Otherwise, they can spend substantial time negotiating a block only to discover a transfer restriction later.
3. IP Reputation
Availability does not guarantee quality.
IPv4 addresses have history.
Previous networks may have used them for:
- Hosting
- Enterprise applications
- Customer infrastructure
Some blocks may also have histories involving spam, malware, abuse, or other problematic activity.
Before businesses buy IPv4 addresses, they should review reputation and relevant blocklist information.
A scarce address should not automatically be considered a good address.
4. Routing History
Buyers should understand how a prefix has been announced historically.
Questions can include:
- Which ASNs originated it?
- Is it currently routed?
- Have there been unusual routing events?
- Are existing route objects present?
- What RPKI configuration exists?
Routing history provides context for deployment planning.
5. Geolocation
An available IPv4 block may have previously operated in a different region.
Some geolocation databases can continue showing the historical country or network even after the resource changes hands.
For location-sensitive applications, buyers should understand this before deployment.
Where Can Businesses Buy IP Addresses?
Organizations generally have several routes to acquiring IPv4.
Direct Transactions
A buyer can identify an IPv4 holder and negotiate directly.
This may work when the parties already know each other or when a buyer has access to suitable resources.
However, direct sourcing can require significant effort.
The buyer must independently manage areas such as:
- Seller discovery
- Resource verification
- Pricing
- Due diligence
- Documentation
- Transfer coordination
Brokers and Intermediaries
Brokers can help identify potential sellers.
This can expand the buyer’s sourcing reach.
However, buyers should understand who controls the resource and what role each intermediary plays in the transaction.
IPv4 Marketplaces
An IPv4 marketplace creates a structured environment where address holders and buyers can meet.
Instead of starting from zero each time an organization needs address space, buyers can use the marketplace to identify resources offered by sellers.
The marketplace model can support:
- Resource discovery
- Buyer and seller matching
- Block comparison
- Due diligence
- Transfer coordination
- Transaction execution
For businesses looking to buy IP addresses, this can make secondary-market sourcing more manageable.
Why Marketplace Supply Changes
One important feature of IPv4 marketplaces is that inventory is dynamic.
Imagine that five different organizations make /24 blocks available this month.
Those blocks may be purchased.
Next month, a network restructuring at another company may release a /20.
The following month, a larger resource holder may decide to transfer several blocks.
This is why buyers should not assume that current listings represent the entire future market.
IPv4 marketplace availability is continuously shaped by decisions made by existing resource holders.
What to Do If the IPv4 Block You Need Is Not Available
A buyer may occasionally find that the exact block size or region it wants is not immediately available.
Several strategies can help.
Expand the Search Window
If the network does not need IPv4 immediately, more suitable inventory may appear over time.
Consider Multiple Blocks
An organization requiring 2,048 addresses might prefer one /21, but depending on routing and operational requirements, multiple smaller prefixes could potentially be considered.
This should be evaluated carefully because more prefixes can increase routing and administrative complexity.
Review RIR Requirements
A buyer may discover additional sourcing possibilities by understanding whether an inter-RIR transfer is appropriate.
Consider Leasing
If permanent IPv4 supply is temporarily unavailable, leasing can potentially provide capacity while the organization continues searching for resources to purchase.
Increase IPv6 Deployment
IPv6 can reduce the amount of new IPv4 required for some workloads, allowing scarce IPv4 to be reserved for services that genuinely need it.
Buy IPv4 or Lease While Waiting?
Availability can influence whether businesses buy or lease.
Suppose a cloud provider ultimately wants to acquire a large IPv4 block.
The exact resource it wants may not currently be available.
Instead of delaying expansion, the company may temporarily lease IPv4 capacity.
This creates a hybrid strategy:
Short-term requirement → IPv4 leasing
Long-term requirement → IPv4 purchasing
Buying and leasing therefore do not always compete.
They can be used together as part of capacity planning.
How an IPv4 Marketplace Helps With Supply Discovery
One of the main functions of an IPv4 marketplace is visibility.
IPv4 resources are distributed across thousands of organizations around the world.
Without a market mechanism, a buyer may have no practical way to know which holders are willing to transfer resources.
A marketplace creates a place where supply can become visible to demand.
For buyers, that means the question can move from:
“Who might have IPv4?”
to:
“Which available IPv4 resources match our requirements?”
That is a much more efficient procurement problem.
What to Prepare Before Entering an IPv4 Marketplace
Buyers can improve their chances of completing an acquisition efficiently by preparing several details in advance.
Required Prefix
Know whether the network requires a /24, /22, /20, or another size.
Preferred RIR
Identify whether a particular registry region is required.
Deployment Timeline
Know when the addresses must become available for production.
Budget
Establish an acceptable acquisition range.
Network Use
Document how the resource will support the organization.
Transfer Readiness
Understand what documentation or recipient approval may be needed.
A prepared buyer can respond faster when suitable IPv4 becomes available.
Why Buyer Readiness Matters in a Limited Market
When supply is finite, good opportunities may attract multiple buyers.
An organization that has not decided its required size, region, budget, or approval process may lose time while another buyer is ready to proceed.
Procurement preparation should therefore happen before a specific block is selected.
Network, finance, legal, and management teams should understand:
- Why the organization needs IPv4
- How many addresses are required
- What the budget is
- Who can approve the transaction
- Which technical requirements matter
This turns IPv4 purchasing from an emergency request into an established infrastructure process.
How i.lease Fits Into IPv4 Supply
i.lease operates as a global IPv4 marketplace supporting secondary-market transactions involving buying, selling, and leasing address space.
Marketplace inventory is naturally dynamic because it depends on real resource holders making IPv4 available.
For organizations looking to buy IPv4, this means availability should be evaluated based on actual marketplace supply rather than an assumption that every size of address block will always be in stock.
The value of an IPv4 marketplace is therefore not that it creates new IPv4 addresses.
It creates a structured mechanism through which existing supply can reach organizations that need it.
Questions to Ask Before Buying Available IPv4
When a suitable block becomes available, buyers should ask:
- Who is the registered resource holder?
- Is the block eligible for transfer?
- Which RIR administers it?
- Does the prefix size match our requirement?
- What is the reputation history?
- Is the resource currently routed?
- What does the routing history show?
- What is the current RPKI status?
- What geolocation history exists?
- What documentation will the transfer require?
- What are the transaction milestones?
- When can the resource realistically be deployed?
Availability should be the start of due diligence—not the end of it.
Common Mistakes When Buying IPv4 in a Limited Market
Waiting Until the Last Minute
Emergency procurement weakens the buyer’s ability to compare options.
Buying Any Available Block
Scarcity should not eliminate due diligence.
Choosing Only by Price
A lower-priced block may create additional reputation, routing, or transfer costs.
Ignoring Growth
Buying only enough IPv4 for today’s requirements can create another shortage quickly.
Assuming Supply Is Static
Marketplace availability changes as resources enter and leave the market.
Ignoring IPv6
Not every future workload necessarily requires dedicated IPv4.
Address planning should determine where IPv4 creates real operational value.
A Better IPv4 Procurement Strategy
A mature IPv4 strategy combines several approaches.
Forecast
Estimate address requirements before capacity becomes critical.
Optimize
Recover unused IPv4 from existing infrastructure.
Deploy IPv6
Reduce unnecessary future dependence on IPv4.
Lease
Use leasing where flexibility or temporary capacity is more important than permanent acquisition.
Buy
Acquire IPv4 where the network has predictable long-term requirements.
Monitor the Marketplace
Stay aware of supply rather than waiting for a shortage.
This provides significantly more flexibility than relying on a single sourcing method.
Final Thoughts
Businesses that need to buy IP addresses are operating in a market defined by finite supply.
IPv4 exhaustion does not mean address space is no longer available.
It means that new demand increasingly has to be matched with IPv4 resources that already exist elsewhere in the Internet ecosystem.
That makes supply dynamic.
The prefix you need may be available today, later, or through a different registry or transaction structure than originally expected.
Organizations should therefore approach IPv4 purchasing as an ongoing capacity-planning process.
Forecast demand.
Define the required block size.
Understand the applicable RIR.
Prepare for transfer.
Check reputation and routing.
And begin sourcing before existing address capacity reaches its limit.
An IPv4 marketplace helps make this process more structured by bringing available address resources and qualified buyers into the same environment.
For organizations planning long-term network growth, the goal should not simply be to find IPv4 addresses for sale.
It should be to secure the right IPv4 capacity, from a verifiable source, at the time the network actually needs it.
Frequently Asked Questions
Are IPv4 addresses still available to buy?
Yes. Although freely available IPv4 pools have been exhausted or constrained, existing address holders can make eligible resources available through the IPv4 secondary market.
Where can businesses buy IPv4 addresses?
Businesses can source IPv4 through direct sellers, intermediaries, or an IPv4 marketplace that connects buyers with resource holders.
Why is IPv4 supply limited?
IPv4 uses a finite 32-bit address space. Global growth consumed the available unallocated pools, so additional demand increasingly depends on existing resources being transferred or leased.
What is an IPv4 marketplace?
An IPv4 marketplace connects organizations that need address space with resource holders offering IPv4 for purchase, sale, or leasing.
How many IPv4 addresses should I buy?
The appropriate quantity depends on current utilization, expected growth, infrastructure plans, reserve capacity, and how much future demand can be served through IPv6.
Can I buy a /24 IPv4 block?
A /24 contains 256 IPv4 addresses. Availability depends on current market supply and whether an eligible block matching the buyer’s requirements is available.
What if the IPv4 block size I need is unavailable?
Buyers can monitor future marketplace inventory, consider different block combinations where operationally appropriate, explore other eligible transfer routes, lease temporary capacity, or reduce some IPv4 demand through IPv6.
Should I buy IPv4 before my existing pool runs out?
Organizations with predictable growth should generally plan address capacity before exhaustion becomes an operational emergency. Earlier planning provides more flexibility around block size, timing, due diligence, and transaction structure.
What should I check before buying available IPv4?
Verify the resource holder, transfer eligibility, RIR, reputation, routing history, RPKI status, geolocation, documentation, and transaction conditions before purchasing.
Does an IPv4 marketplace create new IPv4 supply?
No. A marketplace helps existing IPv4 resources move from organizations with available address space to organizations that need additional capacity.
Leave a Comment