Inter-RIR Transfers: Moving IPv4 from ARIN to RIPE in 2026

Inter-RIR Transfers: Moving IPv4 from ARIN to RIPE in 2026

Short answer (checked 2026-10-29): ARIN's public transfer log lists 748 IPv4 transfers from ARIN to the RIPE NCC in 2026 up to 28 October, almost double the 378 of the whole of 2025. Only 37 went the other way. The ARIN side runs under NRPM section 8.4, the RIPE side under RIPE-807 section 3.2, and the request always starts at ARIN. Neither registry publishes a fixed timeline, so plan the paperwork before you plan the date. Market context lives on /ipv4/pricing.

Checked on 2026-10-29. ARIN: NRPM section 8.4, the ARIN transfer page and the fee schedule (effective 1 January 2026). RIPE NCC: RIPE-807, Resource Transfer Policies and the inter-RIR transfer page. Counts: ARIN's transfer log, newest entry 2026-10-28.

What ARIN's transfer log shows

Every RIR publishes its transfers as JSON in a shared format, with source_rir and recipient_rir on each record. The script below reads ARIN's file, keeps the IPv4 transfers between ARIN and the RIPE NCC and prints them per year: count, addresses moved and the median block. Python 3, standard library only. Save it as rir_flows.py:

#!/usr/bin/env python3
"""Inter-RIR IPv4 transfers between ARIN and the RIPE NCC, per year, from ARIN's public log."""
import ipaddress
import json
import sys
import urllib.request
from collections import defaultdict
from statistics import median

URL = "https://ftp.arin.net/pub/stats/arin/transfers/transfers_latest.json"
with urllib.request.urlopen(URL, timeout=60) as r:
    log = json.load(r)["transfers"]

def ip(s):  # the log zero-pads octets ("204.016.240.000"), which ipaddress rejects
    return int(ipaddress.IPv4Address(".".join(str(int(o)) for o in s.split("."))))

def addresses(t):
    nets = t.get("ip4nets", {}).get("transfer_set", [])
    return sum(ip(n["end_address"]) - ip(n["start_address"]) + 1 for n in nets)

flows = defaultdict(list)  # (year, direction) -> addresses per transfer
for t in log:
    src, dst = t.get("source_rir"), t.get("recipient_rir")
    ips = addresses(t)
    if ips and {src, dst} == {"ARIN", "RIPE NCC"}:
        flows[(t["transfer_date"][:4], f"{src} -> {dst}")].append(ips)

since = sys.argv[1] if len(sys.argv) > 1 else "2021"
print("ARIN transfer log, newest entry", max(t["transfer_date"] for t in log)[:10])
print("year  direction           transfers   addresses  median")
for (year, way), sizes in sorted(flows.items()):
    if year >= since:
        prefix = 33 - int(median(sizes)).bit_length()  # 1024 -> /22
        print(f"{year:<6}{way:<20}{len(sizes):>9}{sum(sizes):>12,}     /{prefix}")

python3 rir_flows.py 2021

Output, run on the author's Linux workstation with Python 3.14.4 on 2026-10-29 (not DCXV Cloud):

ARIN transfer log, newest entry 2026-10-28
year  direction           transfers   addresses  median
2021  ARIN -> RIPE NCC          165   1,870,848     /20
2021  RIPE NCC -> ARIN           95     153,088     /23
2022  ARIN -> RIPE NCC          125   6,434,048     /22
2022  RIPE NCC -> ARIN          104   2,183,680     /22
2023  ARIN -> RIPE NCC          214   7,736,576     /22
2023  RIPE NCC -> ARIN           51   2,007,296     /19
2024  ARIN -> RIPE NCC          185   7,871,232     /18
2024  RIPE NCC -> ARIN          138   4,171,008     /20
2025  ARIN -> RIPE NCC          378  10,068,736     /22
2025  RIPE NCC -> ARIN           71   1,114,112     /22
2026  ARIN -> RIPE NCC          748   6,095,104     /20
2026  RIPE NCC -> ARIN           37   1,340,160     /18

How to read it. The flow runs one way: since 2021, every year sent more transfers from ARIN to the RIPE NCC than back. 2026 is a partial year and already has the most transfers in the series, but fewer addresses than 2025: more deals, fewer very large blocks. The median is rounded down to a whole prefix. In 2026 the busiest month was April (147 transfers) and the most common sizes were /20 (150 transfers) and /19 (125); 123 were a single /24. The log counts registry events, not prices: it says nothing about what each block sold for. For the RIPE NCC's own view, run the same script against https://ftp.ripe.net/pub/stats/ripencc/transfers/transfers_latest.json.

Why the space moves east

• The RIPE region has no free pool. A new LIR can join the waiting list for one /24, and the wait is measured in months; the numbers are in RIPE waiting list vs buying a /24. Anything larger comes from the market.
• The oldest space sits in the ARIN region. Most legacy blocks, registered before ARIN was founded in 1997, are held there, and ARIN-region holders can sell to the RIPE region under 8.4.
• The rules are compatible. ARIN only transfers to registries whose policy is needs-based; the RIPE NCC meets that by asking the recipient for a plan to use at least half of the space within five years (RIPE-807, section 3.2).

Region-specific notes are on /ipv4/arin and /ipv4/ripe.

The rules on each side

	ARIN (source)	RIPE NCC (recipient)
Policy	NRPM 8.4	RIPE-807 section 3.2 and the inter-RIR page
Eligibility	Registered holder, no dispute; no IPv4 received from ARIN in the past 12 months (common ownership excepted); minimum /24	Network with an active element in the RIPE region; a contract with the RIPE NCC (an LIR, or a sponsoring LIR for ASSIGNED PI); a plan to use 50% within five years
Documents	Signed and notarised Officer Acknowledgement Letter	Recent registration document; confirmation letter signed by a director; the status wanted: ALLOCATED PA, ASSIGNED PI or LEGACY
Registry fee	$500 source transfer request fee (schedule effective 1 January 2026)	None for the transfer; LIR membership fees apply (RIPE-867)
After the transfer	Source barred from the ARIN waitlist for 36 months	No re-transfer for 24 months (RIPE-807 section 2.2.1)

Two details catch people out. Legacy space can arrive in the RIPE region as LEGACY without a contract, but RPKI then needs one. And IPv6 cannot move between ARIN and another RIR at all.

Step by step

1. Agree the deal and check the block. Who is the registered holder at ARIN, is anything in dispute, is the range clean? Use the blacklist check before buying and agree how money is held: IPv4 escrow milestones.
2. Prepare the RIPE side first. The recipient needs an LIR (or a sponsoring LIR for PI), the registration document, the signed confirmation letter and the 50% plan.
3. The source files at ARIN. A point of contact of the ARIN-region organisation submits the 8.4 request in ARIN Online, with the notarised letter, and pays the $500 fee.
4. ARIN approves, then hands over. ARIN contacts the RIPE NCC, which contacts the recipient, runs its own due diligence and reviews the documents. ARIN may ask the RIPE NCC to certify the recipient.
5. Both databases change on one agreed date. The network record leaves ARIN and the RIPE NCC creates the objects in the RIPE Database.
6. Make it routable. The recipient creates route and domain objects; an RPKI certificate is issued within minutes if the space is certifiable, reverse DNS can take up to 24 hours. Then fix geolocation: GeoIP after a transfer.

Why it takes longer, and where it stalls

The RIPE NCC says inter-RIR transfers take longer than transfers inside its region because two registries coordinate across time zones; ARIN says the time "can vary". Neither gives a number, and we do not either. Where a deal stalls, going by the rules above:

• The ARIN organisation record or its point of contact is out of date, so nobody can file the request.
• The source received IPv4 from ARIN in the past 12 months, which blocks 8.4 until the year is up.
• The recipient has no RIPE NCC contract yet, or no usage plan.
• Funds move before both registries confirm.

A broker earns its fee on exactly these points: checking the ARIN record and the signatory before money moves, holding funds until the RIPE Database shows the new holder, and keeping both registries' paperwork in step. DCXV charges EUR 2.00 per IP for a /24 or /23 and EUR 1.00 per IP for a /22 to a /19. For scale, the ip4.market 90-day median for a /24 was $25.40 per IP in sales to 2026-10-26. The service page is inter-RIR transfers; the RIPE-only process is in the RIPE NCC transfer guide.

Planning a move from ARIN to the RIPE region? Talk to the IPv4 desk or email ipv4@dcxv.com.