One Number – On the move with your landline number
With One Number, you decide which of your Telekom numbers is displayed – even when you call from your smartphone. Your business partners will immediately recognise who is calling. And your mobile number remains confidential. Monthly price per subscriber €4.95 net
Uniform number display builds trust among business partners – even when you are on the move.
Flexible configuration
Individually customisable via app or web – e.g. temporarily deactivate or define exceptions.
Protecting privacy
Mobile number remains hidden – visible only to specific contacts upon request.
MultiSIM and international compatibility
Also works with MultiSIM and for calls from abroad – with no effort at all.
One number. Many smart features.
Display landline number on mobile
Display your landline number when calling from your smartphone – your customers and partners will immediately recognise who is calling. This ensures a consistent public image and professional communication.
Flexibly adjust settings
Control One Number conveniently via the app or on the web – for example, deactivate the service at weekends or set specific periods for use.
Mobile number visible to selected contacts
Define exception rules for specific contacts where your mobile number is displayed instead of your landline number – e.g. for internal communication.
Works on all devices
Whether you use a smartphone, tablet or business mobile phone with MultiSIM, One Number displays your landline number wherever you want to be reachable.
Accessible worldwide with a landline number
Even when making calls from abroad, you can maintain your professional image – One Number reliably transmits your German landline number.
Compatible with modern connections
One Number works seamlessly with Telekom's SIP trunk and cloud PBX solutions. This means your communications remain future-proof even as your infrastructure grows.
The solution for a professional image for small and medium-sized enterprises
– Without much effort or high costs.
Display of landline
for outgoing mobile connections
All calls are received on the landline number at the office – no disruptive calls on your mobile phone.
With One Number, you can use your landline number flexibly on your smartphone – no matter where you are calling from. Your customers and partners will always see your usual landline number. This gives you numerous advantages:
Mobile phone number remains confidential
Consistent, professional image
Head office or branch office can be defined as a single number
Can also be used abroad
Caller ID transfer even with MultiSIM
Display mobile phone numbers to selected contacts
Can be configured at any time via the app
Protecting your private mobile phone number
Quick to set up
You can deactivate the service, for example, at weekends or during holidays, in order to make calls using your mobile phone number. Exceptions can be defined for private contacts so that your mobile phone number is displayed to them. This can be controlled flexibly via the OneNumber app (for Android and iOS) or on the web via the Call Manager.
The One Number configuration is carried out via the Telekom Callmanager on the web or via the free Telekom One Number app on your smartphone. Even when the service is activated, you can still display your mobile number for up to 75 contacts. The app is available in the App Store and on Google Play.
You can download the app directly from the store here:
If you use a Telekom Germany SIP trunk or an ISDN connection on your landline, or if you would like to book One Number for multiple cards, please use our order form.
To use One Number, you need:
A mobile phone and landline connection with Deutsche Telekom
An IP connection or a system connection with multiple extensions
Please note:
Telekom CallManager and One Number App are not available in combination with Business Voice VPN.
You may only provide or enter mobile or landline numbers (geographic numbers, no service numbers; no speed dial numbers, only German numbers) that have been assigned to you and for which you have a right of use for transmission to the public telecommunications network. Other numbers, e.g. 0137, 0900, 012, as well as emergency services 110 and 112, may not be used in accordance with Section 120 (2) of the Telecommunications Act.
