Mobile glossary for Luxembourg: 5G, roaming, eSIM and all terms explained

Network generations — 2G, 3G, 4G, 5G

Mobile networks have evolved through « generations ». Each generation brings improvements in speed, capacity and latency.

Sources: POST Luxembourg — 5G frequencies · ILR

Data, GB, MB — understanding data volumes

Data (mobile data)

Any flow of information between your smartphone and the internet via your operator’s network — excluding classic voice calls and SMS. Every time you open an app, load a web page, watch a video or receive an email with an attachment without being on Wi-Fi, you consume data.

GB (Gigabyte)

The unit of measurement for mobile data volumes. 1 GB = 1,000 MB = 1,000,000 KB. This is the unit used for mobile plans (e.g. « 20 GB/month included »).

MB (Megabyte)

Sub-unit of GB. 1,000 MB = 1 GB. Used for small consumption figures (a photo = 2 to 5 MB, a text email = a few KB, an app update = 50 MB to several GB).

Speed (or connection speed)

Speed at which data travels, measured in Mbit/s or Gbit/s. Note: speeds are measured in bits, not bytes — 1 byte = 8 bits. A speed of 100 Mbit/s = 12.5 MB/s effective download.

Latency

Delay between sending a request and receiving a response, measured in milliseconds (ms). Low latency is crucial for online gaming, video calls and real-time applications. 4G: ~20-30 ms. 5G: under 10 ms.

Out-of-bundle usage

Consumption beyond the volume included in your monthly plan. Out-of-bundle communications are billed at a significantly higher rate. The Blocked Plan option (available at all Luxembourg operators) prevents any out-of-bundle by blocking communications once the monthly volume is exhausted.

Roaming — staying connected while travelling

Roaming

Use of your Luxembourg mobile plan on a foreign operator’s network when you are abroad. Outside of zones covered by « Roam Like At Home », roaming can trigger significant extra charges.

Roam Like At Home (RLAH)

European regulation (EU 2022/612, valid until 2032) that allows you to use your Luxembourg plan in all EEA countries (EU + Iceland, Liechtenstein, Norway) under the same conditions as in Luxembourg — at no extra cost. Calls, SMS and data work normally in France, Belgium, Germany, Spain and all EU countries.

EEA (European Economic Area)

The geographic zone covered by Roam Like At Home: the 27 EU countries + Iceland, Liechtenstein and Norway. The UK and Switzerland are not part of it following Brexit, but the three main Luxembourg operators voluntarily include them in their no-surcharge zone.

Fair Use

Clause allowing operators to act if a customer uses their plan « mainly or exclusively » outside Luxembourg. In practice, this does not affect cross-border workers, travellers or holidaymakers.

Out-of-EEA data surcharge

Capped billing applicable to data consumed outside the EEA. The European Commission caps the maximum surcharges: €1.30/GB in 2025, €1.10/GB in 2026, €1/GB in 2027.

Source: European Commission — EU Regulation 2022/612 Roam Like At Home

SIM, eSIM, nano-SIM — the identity cards of your line

SIM (Subscriber Identity Module)

A physical chip card that identifies your line to your operator’s network. Physical SIMs come in three formats: standard (large), micro-SIM and nano-SIM.

Nano-SIM

The most common physical SIM card format today. Dimensions: 12.3 × 8.8 mm. Used in all iPhones since the iPhone 5 (2012) and the vast majority of recent Android devices.

eSIM (embedded SIM)

A virtual SIM card integrated directly into the smartphone’s circuit board. Activated digitally via a QR code or app — no physical card to insert. Enables dual number on a single phone. Compatible: iPhone XS and later, Samsung Galaxy S20 and later, Google Pixel 3 and later. In Luxembourg, POST (eSIM at €5), Tango (free eSIM) and Orange offer eSIM.

Dual SIM

A phone capable of managing two lines simultaneously: two physical SIMs or one physical SIM + one eSIM. Particularly useful for professionals and cross-border workers.

IMEI (International Mobile Equipment Identity)

A unique 15-digit number identifying your phone. Dial *#06# to display it. Useful if your phone is stolen to have the device blocked.

EID (Embedded Identity Document)

A unique 32-digit number identifying the eSIM chip in your smartphone. If the EID appears when you dial *#06#, your phone is eSIM compatible.

Source: Apple Support (LU) — eSIM · official Luxembourg operator websites

For everything about eSIM in Luxembourg, see our complete eSIM Luxembourg guide.

Mobile plan vocabulary

Mobile plan (or subscription)

A monthly contract with a mobile operator giving you a defined volume of calls, SMS and data in exchange for a fixed monthly payment. Unlike prepaid, billing is postpaid (invoice at end of month).

SIM-only plan

A plan without an included phone — you receive only a SIM card. The most economical option if you already have a phone. In Luxembourg, all Tango GO)) mobile plans are available SIM-only without commitment.

Commitment / fixed-term contract

A minimum period during which you commit to staying with an operator. In Luxembourg, commitments are 12 or 24 months maximum. Early termination generally requires paying the remaining monthly fees.

No-contract plan

A plan with no minimum period — cancellable at any time with one month’s notice, without penalty. In Luxembourg, Tango (full GO)) range without smartphone), Orange Luxembourg and Eltrona offer entirely no-contract plans. See our no-contract mobile plans guide.

Blocked Plan option

An option available at all Luxembourg operators that automatically blocks all communications once the monthly included volume is exhausted. Activated by default on Tango GO)) Kids Mobile. Costs approximately €2/month at POST.

Units

In some Luxembourg plans, calls and SMS are counted in « units » where 1 unit = 1 minute of call = 1 SMS.

Prepaid

A mobile option where you top up credit in advance and consume from it. In Luxembourg, prepaid cards are: Tango Prepaid (GO))), POST TipTop and Orange Hello. See our prepaid SIM card guide.

Operators, MVNO, network

Network operator (MNO — Mobile Network Operator)

A company that owns and operates its own mobile network infrastructure. In Luxembourg, there are four MNOs: POST Luxembourg (widest network, « Best in Test » MWC 2024), Tango (Proximus subsidiary), Orange Luxembourg and Luxembourg Online (LOL).

MVNO (Mobile Virtual Network Operator)

A virtual mobile operator that offers mobile plans without owning its own network. In Luxembourg, Eltrona is a MVNO using the POST network. Coverage and network quality are identical to those of the host operator.

Network coverage

Geographic areas where the operator’s network is available. 4G coverage is near-total at the three main operators. 5G coverage is more concentrated in urban areas for Tango and Orange, while POST covers more of the national territory. See our mobile network coverage guide.

Frequency band

Range of radio frequencies used for mobile communications. In Luxembourg, the 5G frequencies awarded in July 2020 are the 700 MHz band (good range, rural coverage) and the 3.6 GHz band (high speeds, dense urban areas).

ILR (Institut Luxembourgeois de Régulation)

The national telecommunications regulator in Luxembourg. Awards frequencies, oversees competition, protects consumer rights and runs the free mediation service. Website: ilr.lu

Source: ILR — Electronic communications · June 2026

Luxembourg-specific mobile features

Data Plus (Tango)

Exclusive Tango feature on GO)) mobile S, M and L plans: unused data from one month is automatically carried over to the next month (valid for one additional month). This feature is unique in Luxembourg among national operators.

Data Boost (Tango)

Option included in Tango GO)) mobile M and L plans: once a year, you can double your monthly data volume at no extra cost. Useful during holidays, a month of intensive travel, or a period of nomadic remote working.

Keep Surfing (Tango)

Option included in the Tango GO)) mobile L plan: once the monthly data allowance is exhausted, the connection continues at reduced speed without additional billing.

GO)) advantage (Tango)

Tango benefits programme for households combining a GO)) fibre subscription and GO)) mobile plans. Each mobile line gets additional monthly data (up to +30 GB) and a monthly discount on Unlimited subscriptions. Up to 5 mobile lines per household.

POP Advantage (POST)

POST benefits programme for customers combining a POP Internet subscription and POP Mobile plans. Up to 6 mobile lines benefit from monthly discounts, additional EU data (up to 65 GB EU) and unlimited mobile internet at weekends in Luxembourg (Friday 8pm — Sunday 11:59pm).

VoLTE (Voice over LTE)

Technology enabling voice calls directly over the 4G network, offering HD audio quality and faster call setup. All Luxembourg operators offer VoLTE, generally activated automatically on compatible smartphones.

WiFi Calling

Feature enabling making and receiving phone calls over a Wi-Fi network when mobile coverage is weak or absent. Available at POST on POP Mobile and BusinessEurope plans. No special app required.

Security and mobile protection

Net Protect (Tango)

Tango network security service that automatically filters fraudulent websites, phishing and malware at the mobile network level — no app to install. Available as an option on GO)) mobile plans and included in GO)) Kids Mobile.

Parental controls

Tools allowing parents to limit and monitor their children’s mobile use. Tango offers Parental Control by Bitdefender (included in GO)) Kids Mobile), which works on the mobile network and on Wi-Fi — an important distinction compared to standard network filters.

SIM PIN code

A 4-digit code protecting your SIM card. After 3 wrong attempts, the SIM locks — unlockable with the PUK code (8 digits) on the SIM packaging or available from your operator.

Garantie+ / Assur+ / Assurance Baloise

Mobile insurance offered by Luxembourg operators covering damage, theft, loss and fraudulent use: Assur+ at POST (S, M, L levels), Garantie+ at POST/DEEP for professionals, Assurance Baloise at Tango.

Number portability and switching operator

Number portability

The right to keep your Luxembourg phone number when switching operator. Portability is free and guaranteed by the ILR. Allow around 5 business days between order and effective activation in practice.

Number transfer (portability)

The action of transferring your number from your previous operator to the new one. The new operator handles all steps with the previous one. You simply need to provide your current number and your SIM’s ICCID when subscribing.

ICCID (Integrated Circuit Card Identifier)

A unique 19-20 digit number on your physical SIM card, used to identify it when requesting portability. Available in your phone settings (iOS: Settings > General > About; Android: Settings > About phone > SIM status) or on the back of the SIM card.

Early termination

Cancelling a plan before the end of the minimum commitment period. Fees generally apply. Exception: if your operator changes its contractual conditions to your detriment, you can cancel free of charge under Luxembourg law.

Cancellation notice period

The period to respect between your cancellation request and the effective end of your contract. In Luxembourg, the standard notice period after the minimum commitment is one month.

Auto-renewal

Automatic renewal of the contract at the end of the minimum commitment period, without action on your part. Your plan continues month by month, cancellable with one month’s notice.

Frequently asked questions about mobile terms