Mixvoip vs DEEP: Which Business Phone Provider Should You Choose in Luxembourg?

Both Mixvoip and DEEP can run a Luxembourg business phone system well, but they start from very different places. DEEP is the B2B brand of POST Luxembourg, the state-owned incumbent that owns the national network, three Tier IV data centres, and sells telephony mostly inside an all-in-one bundle. Mixvoip is an independent business-telephony operator, the second largest fixed-line operator in Luxembourg, that also provides internet, mobile, IPTV, and IT and security services across four countries. That single difference shapes almost every practical choice below.

This guide compares them the way a telecom consultant would, not a brochure. The right answer depends on your company size, your existing infrastructure, the Cloud PBX features you actually need, how much you work across borders, how much pricing visibility you want before you commit, and the support you expect.

Mixvoip is a Luxembourg operator that has provided business voice since 2008. Its core products are Cloud PBX (Voxbi), SIP trunks, business internet, mobile, IPTV, and IT and security services across Luxembourg, Belgium, Germany, and France. It is regulated by the ILR and by the equivalent authority in each country it serves. It offers a softphone for web, Windows, macOS, iOS, and Android, markets its telephony as independent of your internet provider, and publishes pricing for core services. It is widely described as the second largest fixed-line operator in Luxembourg. The full Mixvoip profile has the detail.

DEEP is the B2B services brand of POST Luxembourg, the state-owned national operator. Launched in 2024, it unified Post Telecom, the EBRC data centres, Elgon IT services, and Digora Luxembourg under one name, with the operational merger completed in early 2025. Its telephony portfolio has several tiers: ConnectedOffice (an all-in-one SME bundle), CloudPBX (Cisco Webex Calling in the POST cloud), Managed UC (Cisco UCM), MS Teams CloudVoice (Microsoft Teams via Direct Routing), and SIP trunks. Pricing is quote only, except the smallest Essentials bundle and mobile plans. The full DEEP profile has the detail.

Each card covers one capability. Green marks a clear practical advantage for one side, amber means it depends on what you want, and grey means the two are broadly even.

The cards above show the what. These toggles cover the so what, the points that change how the system feels to run day to day.

For a freelancer or very small team, Mixvoip is the realistic choice, with public pricing and a fast start, while DEEP's bundles and longer contracts are heavier than a micro business needs.

For an SME of 5 to 50 people, Mixvoip usually fits best for transparent entry, ISP independence, and a modern softphone. DEEP is worth a look if you already buy its internet or want one managed bundle for everything.

For a multi-site company across the Greater Region, Mixvoip suits firms that want numbers and presence in Luxembourg, Belgium, Germany, and France. DEEP suits groups whose footprint is mainly Luxembourg and who value a single national operator.

For teams with many field or mobile workers, Mixvoip leads on its multi-platform softphone and mobile integration, though DEEP's fixed-mobile convergence covers the cross-border worker case too.

For a company already on POST connectivity or a Cisco estate, DEEP keeps everything in one contract. It is still worth comparing the all-in cost per user.

For advanced integrations or SIP trunk flexibility, Mixvoip is the stronger contact. For a CSSF-regulated or public-sector organisation that needs PFS status, Tier IV Luxembourg hosting, and full single-vendor scope, DEEP is a strong fit.

There is no universal winner. Mixvoip is usually the better first call when you want Cloud PBX flexibility, public pricing, a modern softphone on every platform, voice that does not depend on one internet supplier, documented integrations, and a presence across the Greater Region.

DEEP is often the better first call when you are a regulated or public-sector buyer that needs PFS status and Tier IV Luxembourg hosting, when you want internet, telephony, security, and data centre from one state-owned vendor, or when you already run POST connectivity or a Cisco estate. The practical move is to shortlist on your current infrastructure, the features you truly need, your numbering and cross-border needs, and your support expectations, then ask both providers the questions above and compare the written answers.