Number Porting Luxembourg 2026: Keep Your Business Number

Your business number is an asset. Customers know it, it is printed on invoices, vehicles, and signage, and it sits in thousands of contact lists. The good news: when you move to a Cloud PBX, you almost always keep it. This guide explains the actual 2026 process in Luxembourg, what it really costs, how long it takes by law, and how the rules differ if you also hold numbers in Belgium, France, or Germany.

Number porting is the process of moving an existing phone number from one operator to another while keeping the number unchanged. The number stays the same; only the operator behind it changes.

The short answer

In Luxembourg, porting a business number to a new operator is a legal right, it is free of charge to you, and the activation must happen within one working day of the date you agree with your new operator. Your new operator runs the whole process. You do not contact your old operator to cancel first.

Who regulates porting in Luxembourg

Number portability in Luxembourg is overseen by the Institut Luxembourgeois de Régulation (ILR). End users who have signed an agreement to transfer a number must have it activated within no more than one working day from the agreed date. The rules sit in ILR regulation 16/204 of 1 April 2016, and operator-side transfers run through a shared central database managed by the operators' porting body, the GIE FNP.

📊 The legal maximum: one working day of downtime. If the transfer fails, your former operator must keep your service running under the same conditions until the new operator is activated.

Get ready and port, in one place

📋 Before you start, gather these. Mismatched details are the top cause of rejection.

The exact legal name on your current telecom account

Your current operator and account or customer number

A recent invoice

The full list of numbers you want to keep

Your current contract end date and any early-exit terms

For French numbers: the RIO code for each line

Then the move runs in six steps.

1️⃣ Choose your operator and sign up. Tell them at sign-up that you want to keep your existing number or numbers.

2️⃣ Provide your details. The new operator needs your exact account details as held today. They must match, or the request can be rejected.

3️⃣ Agree a porting date. You set a date together. This matters if you are still inside a contract term.

4️⃣ The new operator runs the transfer. They submit the request and coordinate with your old operator.

5️⃣ Keep the old line active. Do not cancel it yourself. The port itself ends the old service.

6️⃣ Activation. On the agreed date the number switches to your Cloud PBX, with at most one working day of interruption.

⚠️ Do not terminate your current contract before the port completes. If the number is released early, you can lose it. Porting is what closes the old contract; you do not cancel separately.

What it costs and how long it takes

Cost first, because it is simple: no direct charge for transferring a phone number may be billed to you in Luxembourg. Portability is a fundamental user right.

Timing has two parts. The legal activation window is one working day once a date is agreed. In practice, ILR procedure also builds in a short lead time, with around five working days between the order and the actual switch while operators validate the request. For one clean number, allow a few working days end to end; larger number ranges or older contracts take longer.

💡 In short: the port itself is free and legally capped at one working day of downtime. Realistic end to end, including validation, is usually about five working days.

The real cost is the system, not the port

Porting is free, so the money question is what you pay monthly after you move: the per-user Cloud PBX licence and any number rental. This is where businesses save or overspend. Published Luxembourg pricing is uneven: some operators list per-user rates, others quote only on request.

💶 Metered per user. Pay a lower monthly base plus your actual call usage. Best when call volume is low or uneven. Mixvoip's Voxbi plans run from about €5 to €17 per user per month, ex VAT, by tier.

📞 Flat-rate per user. A fixed monthly fee with unlimited calling to many destinations. Best for heavy or predictable callers. Voxbi flat plans run from about €12 to €24 per user per month, ex VAT.

☎️ Shared-phone licence. A handset with no fixed user, billed cheaper. Ideal for reception, warehouse, or meeting-room phones. From about €3 to €7 per month, ex VAT.

🔌 SIP trunk, keep your PBX. Reuse your existing phone system and just change the line behind it. Mixvoip's SIP flat-rate is €9.90 per user per month for certified systems.

✅ Five ways to keep the bill down

Match plan to use: metered for light callers, flat-rate only for heavy ones.

Use shared-phone licences for low-use handsets instead of full user seats.

Port all your numbers in one batch to avoid repeat coordination.

If your current PBX still works, ask about a SIP trunk instead of full migration.

Run all four countries under one regulated operator: one contract, one invoice, fewer fees.

⚠️ Watch the fine print. Porting is free, but leaving a fixed contract early can still trigger early-termination fees from your old operator. Compare those against the savings before you set a date.

Common mistakes to avoid

Mismatched account details are the single most common cause of rejection: the name on the porting form must match the name registered with the losing operator. Cancelling the old line early is the second. Forgetting that an early exit from a fixed contract can trigger early-termination fees is the third. Porting is free; leaving your old contract early may not be.

If you also hold numbers in Belgium, France, or Germany

Many Luxembourg businesses run cross-border. The right to keep your number exists across the EU, but each country has its own regulator, process, cost rule, and timeframe.

🇧🇪 Belgium, BIPT. Transfers run through a central porting database and take one working day at the most after validation. The new operator manages it. If porting runs late, you can claim delay compensation of 3 to 5 euros per day from your new operator, within six months.

🇫🇷 France, ARCEP. Every fixed number needs a RIO code (Relevé d'Identité Opérateur), a unique line identifier. Get it free from your operator, for example by calling 3179 from the line, then give it to your new operator. Porting is free and automatically ends your old contract, though exit fees may still apply.

🇩🇪 Germany, Bundesnetzagentur. Porting is a legal right under §59 TKG. Unlike Luxembourg, a small capped one-time switch fee is allowed (historically around 6.82 euros). If downtime runs over one working day, you can claim 10 euros or 20 percent of the monthly fee per extra day. A number can usually still be ported for about 30 days after the old contract ends.

Which option fits: operator, SIP trunk, or global platform

This is the practical question of who to buy from. There are three routes, and the right one depends on how cross-border you are and whether you keep your current phone system.

🏢 A regulated local operator. Allocates real Luxembourg numbers and runs porting under ILR rules. Choose this if you want one accountable provider for numbers, porting, and support in the Greater Region. Only an operator registered with each national regulator can port that country's numbers.

🔌 A SIP trunk behind your PBX. Keeps your existing phone system and swaps only the line. Choose this if your current PBX still meets your needs and you mainly want lower call costs and number portability without a full migration.

🌍 A global UC platform. International coverage and rich software, but numbering and porting still depend on local regulatory presence. Choose this if you are a large, multi-country team already standardised on one platform.

For a cross-border business, the strongest test is simple: is the provider a regulated operator in each country where you need numbers? As one example, Mixvoip is registered with the regulators in Luxembourg (ILR), Belgium (IBPT), and France (ARCEP), and operates a German entity in Trier, so it can initiate and complete porting across all four under local rules. To check any provider independently, the ILR publishes a public list of all notified operators in Luxembourg.

📚 Terms you can look up: Cloud PBX, SIP trunk, geographic number, DID (direct inward dialing), VoIP. See the glossary for plain-language definitions.

Phone Number Porting in Luxembourg in 2026: How to Keep Your Business Number When Moving to Cloud PBX