DUStel Tarife: starter, business flex und complete

DUStel Starter

DUStel

DUStel starter

Entry without risk

It couldn't be simpler.

The DUStel starter is a free tariff with which you can test our services without any obligation or use them permanently. It already offers you extensive services that leave hardly anything to be desired. Make calls on a credit basis (prepaid) and start with free 30 minutes to the "German fixed network" (starting credit).

Of course, you can also automate the charging of your tariff by direct debit authorization, set up call forwarding or group calls, use a variety of fax services ... and much more.

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DUStel

DUStel complete

strong and complete for private customers

Our private customer tariff that leaves nothing to be desired.

With DUStel complete, you receive a comprehensive service package, including a flat rate to the German landline network, up to 10 local numbers and just as many SIP connections. You can also book additional flat rates, e.g. to the German mobile network.

The postpaid-based tariff also offers a variety of security features, such as encryption or time and credit limits. Regardless of which IP end devices you use, whether IP telephones or a small PBX such as the FritzBox, our customer center always supports you as an additional virtual telephone system.

Making calls with the DUStel complete is therefore not only very inexpensive, but also extremely relaxing.

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DUStel Complete
DUStel Business Flex

DUStel

DUStel business flex

Designed for business

Customize our tariff to your needs and choose only the options you need.

Whether you are a sole trader, medium-sized or large company, the DUStel business flex always fits, because you can put together your own individual tariff. Regardless of whether you use your existing telecommunications system or simply IP telephones, a FritzBox or other IP end devices.

Our customer center is available to support you in all constellations as a virtual telephone system or as a comprehensive cloud solution - clear, self-explanatory and multi-client capable.

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Tariff overview

All services at a glance - choose the right DUStel tariff for you.

DUStel

starter

€ 0,00
  • No basic fee
  • No contract term
  • Billing to the second
  • Billing to the minute (optional)
  • 2 incoming lines
  • 2 outgoing lines
  • Up to 5 SIP connections
  • incl. starting credit
  • on a credit basis (prepaid)
  • Automated charging possible (optional)
  • New local numbers (optional, see below for costs)
  • Number porting (optional, see below for costs)
  • TLS & SRTP (optional, free of charge)
  • Email-to-Fax & T.38 Fax
  • Fax-to-eMail (phone number required)
  • Forwarding & group call
  • Many security functions
  • Speed dials
  • Connection prices
  • further information see below
order now

DUStel

business flex

from € 10,02* / month

* all business flex prices are net plus 19% VAT.

  • Contract term 1 month
  • Billing to the second
  • from 2/2 lines incoming/outgoing (additional lines bookable, subject to charge)
  • D-flat rate landline (optional, subject to a charge)
  • D-Flatrate mobile communications (optional, subject to a charge)
  • from 2 SIP connections (DDI-capable, additional connections can be booked, subject to a charge)
  • Monthly billing, postpaid
  • Number porting (optional, free of charge)
  • New local numbers (optional, subject to a charge)
  • TLS & SRTP (optional, free of charge)
  • Email-to-Fax & T.38 Fax
  • Fax-to-eMail (phone number required)
  • Forwarding & group call (also time-controlled)
  • Own music on hold / sound logo
  • IVR menu (optional, subject to a charge)
  • ACD system (optional, subject to a charge)
  • CLIPnoScreening (optional, chargeable, phone number required)
  • Many security functions
  • Speed dials
  • Connection prices
  • further information see below
assemble now

DUStel

complete

from € 7,90 / month
  • for private use only
  • Contract term 12 months
  • Billing to the second
  • 2 incoming lines
  • 2 outgoing lines
  • 1x D-flat rate landline (included)
  • Second D-flat rate fixed network (optional, + EUR 4.90)
  • D-Flatrate mobile (optional, + EUR 6.90)
  • Up to 10 SIP connections (included)
  • Monthly billing, postpaid
  • Up to 10 new local numbers (included, free of charge)
  • Number porting (optional, free of charge)
  • TLS & SRTP (optional, free of charge)
  • Email-to-Fax & T.38 Fax
  • Fax-to-eMail (phone number required)
  • Forwarding & group call
  • Many security functions
  • Speed dials
  • Connection prices
  • further information see below
order now

Quickly & transparently explained ...

Details on porting, phone numbers, payment and functions. Open areas are saved in this browser (localStorage).

Note: The provider change can only be ordered via the customer center. To do this, you first need a tariff such as DUStel starter, complete or business flex. When you book one of these tariffs, you automatically receive access to the customer center.

DUStel starter

The number portability (import) of one or more of your phone numbers to dus.net is free of charge. The transfer of your existing number(s) to another provider (export) is also free of charge
. From 01.02.2026, DUStel starter will charge an annual administration fee of EUR 1.50 (incl. VAT) for each ported telephone number.

Example:
- One telephone number is ported to dus.net = EUR 1.50/per year
- 5 phone numbers are ported to dus.net = EUR 7.50/per year
- 10 phone numbers are ported to dus.net = EUR 15.00/per year

!!! For provider changes made before 01.02.2026, the previous regulation still applies !!!

DUStel business flex

The number portability (import) of one or more of your phone numbers and also of phone number blocks to dus.net is free of charge. When ordering, you should always select a tariff that is large enough in terms of numbers to match the number of imported numbers. Example: If you would like to import a block of 30 numbers (with or without interrogator) into the DUStel business flex, then select at least a block of 30 numbers when ordering the tariff under Numbers. If you select a block of 100 instead, you can order 70 additional new phone numbers (also as a block) or import additional phone numbers/blocks in addition to your imported block of 30.

DUStel complete

With DUStel complete, there are no porting costs or administration fees for up to 10 numbers. Everything is already covered by the basic monthly fee.

General information

You must continue to use the local network even after porting. It is not permitted to port phone numbers from one local network to another local network if you change your place of residence or company headquarters at the same time.

The provider change date is always determined by the transferring provider and usually coincides with the end of the contract term. During the contract term, numbers are not released prematurely by the transferring provider. There are only exceptions, if any, for pure VoIP providers or if you have made a special arrangement with the old provider.

Removing individual phone numbers from a contract is usually only possible with pure VoIP providers. Providers such as Telekom or Vodafone do not allow this. These providers only surrender the phone numbers as a whole or individually if the remaining numbers are dropped at the same time and only in connection with a line termination. The following applies to all providers, including us: it is of course not possible to remove individual numbers from system connections or number blocks.

Note: You can only order a phone number via the customer center. To do this, you first need a tariff such as DUStel starter, complete or business flex. When you book one of these tariffs, you automatically receive access to the customer center.

DUStel starter

New local numbers are charged at EUR 9.90 once for the DUStel starter tariff and EUR 5.00 annually in advance (both prices incl. VAT). Numbers must be canceled at least 14 days before the end of the billing year if they are no longer required. Disconnection is of course also possible within the annual period, but in this case no refund of the administration fee for the unused period can be made.

DUStel complete

With DUStel complete, up to 10 local numbers are already included in the basic monthly rate and can be ordered optionally.

DUStel business flex

In the DUStel business flex tariff, there are no one-off costs, but there are monthly costs per local network number, which are included in the monthly basic charge. Individual numbers or number blocks can be ordered. The desired quantity is specified when ordering the tariff and ordered in the customer center once the tariff has been activated. Of course, the quantity can be adjusted at any time so that additional numbers can be ordered at short notice.

How to order

Local numbers are always ordered via the customer center, not via the tariff booking. Only with DUStel business flex do you specify the number of local numbers to be ordered when booking the tariff. For new local network numbers, the local network reference must be available (!!!). Numbers can only ever be obtained from the local network of the place of residence or company headquarters (or branch office or temporary residence).

DUStel starter

Our prepaid tariff DUStel starter is based on credit. Here, credit must be topped up in order to be able to make calls. The credit can be topped up by bank transfer, direct debit (also automated) or Paypal. Of course, direct debit requires a valid SEPA direct debit mandate.

The top-up via PayPal is posted in real time, provided it is at least the second payment from the same PayPal account. The first payment is checked manually by us before it is credited. Automated charging by direct debit is not a real-time application. Here, the current account balance is only ever checked at night and only then topped up if necessary. You should therefore always have sufficient minimum credit available when using automated top-up.

DUStel complete and DUStel business flex

Our DUStel complete and business flex tariffs are postpaid tariffs and require a valid SEPA direct debit mandate. The call costs incurred in a month are charged within the first few days of the following month, together with the basic charge for the current month, and collected by SEPA direct debit.

Public institutions and authorities that do not support SEPA direct debit are of course billed by invoice. This applies to both the DUStel starter and the DUStel business flex.

All our tariffs offer extensive faxing options. Of course, a local telephone number is required for incoming calls. With the fax-to-email function (EUR 0.03 per received page, incl. VAT), incoming faxes are converted directly into a PDF document on our system and sent to you by e-mail. A free fax-to-email option is no longer offered.

Outgoing faxes can be uploaded and sent directly as a PDF document via the customer center. Another very convenient option is the email-to-fax function (subject to a charge). Here you send a fax via your email client with the PDF document attached. The subject is predefined and the fax number is entered as the recipient (faxnummer@fax.dus.net).

For all those who prefer the classic fax machine or those who still need to use one, the T.38 protocol is available. Getting fax signals over an Internet line without interference is not always successful. The problem is that fax machines are hardly fault-tolerant. Even the slightest interference can lead to a complete interruption.

The T.38 protocol processes the fax signal digitally and "corrects" errors so that both fax machines remain stable during transmission. If no T.38 is supported on the other end, at least the route from you to our server or vice versa is "quality assured".

Encryption with TLS or with TLS & SRTP is generally possible in each of our tariffs. However, your SIP end devices must also support this. By default, encrypted telephony at dus.net always uses TLS (for the SIP packets) and SRTP (for the media stream). Some SIP end devices may only be able to use TLS without SRTP. In this case, you can simply deactivate support for SRTP for each connection in the customer center.

It is also important to know that encrypted telephony between your end device and our SIP server ends there. The transfer to the landline network, mobile network or VoIP network of other providers is then unencrypted. This also applies to call forwarding or group calls within dus.net. Encryption is no longer technically feasible here. This means that encryption is activated between our server and your end device, but not when the call is forwarded to third party end devices.

Further technical information and necessary settings can be found here.

Full emergency call functionality is of course provided. Calls to 110 and 112 always reach the relevant control center in your area. However, it should be noted here that correct emergency call functionality is no longer possible with normal use of telephony. If, for example, you use your private "home number" in a hotel in another city, the emergency call would of course reach the control center of your place of residence and not that of the place where you are actually located.

The additional security functions we provide are varied and extensive. You can limit calls in terms of time (security limit) and cost (credit limit). You can block incoming calls via the blacklist or only allow selected incoming calls via the whitelist. A Destination network release restricts your outgoing telephony as required. Here you specify which destinations you want to allow, e.g. only all Germany-wide destinations or Germany-wide destinations without the 0137 line. Or you can allow all European destinations, with landline and/or mobile networks.

If you have a fixed IP address or you know the network or networks from which you receive an IP address, you can use the IP address restriction to restrict outgoing telephony. If an unauthorized person gains access to your SIP user data and you have stored your IP address or IP network, the use of telephony by third parties is virtually impossible.

Call forwarding

Call forwarding allows two scenarios. Either your IP telephone rings first and then other forwarding destinations, or the forwarding destinations are addressed directly without your IP telephone ringing first. If the first scenario is set up but your IP telephone is unavailable or busy (both can be set), forwarding will of course take effect immediately. You can enter up to 10 forwarding destinations in total, two of which can be external destinations.

Group call (parallel call)

With group call, your telephone always rings together or in parallel with the configured parallel call destinations (group). Your IP telephone is therefore part of a group. Here too, up to 10 parallel call destinations can be entered, two of which can also be entered as external destinations.

General information

Call forwarding and group calls are always set up in relation to the SIP connection. A phone number or several phone numbers are then assigned to a SIP connection via routing. If other SIP connections are to be defined as destinations (internal destinations), the user name (000387xxxxxx) is entered as the destination and not the phone number assigned to the SIP connection.

If call forwarding or a group call is already configured on the SIP connection that is to serve as the destination, this SIP connection cannot be a forwarding or group destination. Forwarding behind a forwarding is not possible. The same applies to group calls or mixed operation of both functions.

You do not need this function if you want to transmit your own phone numbers connected to us as CLIP. This function is intended exclusively for transmitting third-party phone numbers. A possible scenario would be, for example: A customer calls you on their cell phone. On your telephone system, you would now like to forward this call to your own cell phone. To transfer the caller's mobile phone number, you now need the CLIPnoScreening function to allow the number to be transferred.

For liability reasons, activation of this function requires a written agreement, which you must sign and send to us. You will receive this upon request or directly when ordering if this feature is desired. In addition, we require a telephone number registered with us to identify you or your company. This number is sent with every outgoing call, but is not displayed to the called party.

You can optionally book a real call distribution system (automated call distribution, queue system), called DUSqueue, with the DUStel business flex tariff.

The DUSqueue is primarily used for order acceptance or support hotlines. All callers are initially "parked" in a queue via a central order or hotline number and remain there until an employee (agent) connected to the system answers the call. The agent logs into the system to be part of the support team and logs out again when they have finished their work. Logging in can be done from anywhere, e.g. from the employee's home office.

The DUSqueue queue system offers a wide range of setting options and also allows you to customize the use of music on hold or announcements when the queue is open or closed. Extensive statistics are also available for perfect evaluation. All calls are counted, totals and average values for waiting times are calculated and much more.

An IVR (Interactive Voice Response) menu is an automated telephone system that guides callers through a menu structure by keystroke or voice to determine their request and route them to the correct department. The system plays prompts such as "Press 1 for..." to connect the customer to a specific contact or to further information, rather than connecting them directly to an employee.
This can be built up from a single level up to several levels. Of course, you can include your own announcements, define individual employee telephones or complete call groups as destinations.