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Call-by-Call ( CbC ) describes the possibility of making phone calls or Internet connections via a provider other than the telephone connection provider. The telephone connection is operated by the so-called subscriber network operator, while the call or Internet connection in the case of call-by-call is established by a different connection network operator . This gives the consumer the opportunity to easily use other - often cheaper - providers. The term call-by-call is a pseudo-Anglicism , the actual English term is dial-around service, in German meaning “bypassing the (actually) assigned service by dialing”, literally “changing dial”.

In the case of a telephone call, the caller dials the connection network operator code before the actual call number . This special number is also known colloquially as economy code, area code or call-by-call number . These numbers are structured according to the pattern 010xy or 0100xy in Germany, 10xy in Austria and 107xy and 108xy in Switzerland.

In the case of Internet access, the dial-in number of the desired provider is dialed. The access data - in particular the username and password - are the same for all users and are published openly by the so-called Internet service provider , which enables quick and uncomplicated use.

For both telephone and Internet-by-call, with the registration-free tariffs prevailing in Germany, there is often the problem that providers make their initially cheap offers more expensive at short notice. This often results in significantly higher costs than expected for customers who do not find out about the current tariffs before each use.


The regular call-by-call procedure is only available in Germany on landline telephone connections from the established connection operator Deutsche Telekom . The procedure was introduced by the legislature in 1998 in order to break the market power (then monopoly position) of Deutsche Telekom. If you select no call-by-call prefix before the conversation is about to connect preset network operator performed (VNB). Without a change (subject to a fee) commissioned by the participant, this is Deutsche Telekom.

Full connections from alternative providers

Telephoning via other line operators than Telekom (e.g. Arcor and numerous local telephone companies) is not possible using the usual 010xx call-by-call. Special 0900 call-by-call providers can be used on the telephone connections of some alternative network operators (e.g. HanseNet , Versatel ) . Call through can be used via all alternative landline providers . Call- through offers that use 0180 and 0700 numbers are used - as is common with open call-by-call in Germany - without registration and the fees for forwarding by the call-through provider are already charged by the uniform connection price for these special numbers. Call-through offers with 0800 or geographical landline dial-in numbers usually offer higher savings potential, but require registration and invoicing is carried out separately by the call-through provider. With the increasing proliferation of DSL - broadband access are increasingly IP telephony and Web-based telephony as a call-by-call options in use.

Call-by-call in the local network

For call-by-call in your own local network, your own area code does not have to be dialed (exception: providers with 0900xy number). It is sufficient here to dial the number immediately after the network code. So if a telephone customer in Berlin wants to reach another connection in Berlin using the network code 010xy, he simply dials 010xy 12345678. Only the area with the same area code counts as the local network. The local area, i.e. connections to neighboring local networks, which is also billed at the Telekom at the local rate, is usually considered to be long-range for call-by-call providers; However, it should be noted that due to market entry barriers specifically set up by the legislator, the intensity of competition for call-by-call in the local network is significantly lower, which means that significantly more providers are available for cross-local network connections and the cheapest offers for such long-distance connections are usually below the Price levels for local calls.

Call-by-call in mobile communications

Call-by-call is not available in mobile communications in Germany . As with full connections from Telecom competitors, call through and callback can be used as an alternative . Various providers provide such services. Depending on the provider, with or without additional software, using special (sometimes free) dial-in numbers, the desired connection is established just as conveniently as with call-by-call in the fixed network. In the case of software solutions, it should be noted that additional costs are incurred for the GPRS data connection. These can be significant due to unfavorable data tariffs (large data blocks of at least 10 KB - 100 KB are often invoiced per data usage). Such services are most frequently used for telephone calls abroad and in the other mobile networks - also known colloquially as "foreign networks".

New forms of call-by-call

Due to the heavy use of broadband connections, IP telephony is increasingly establishing itself as a new form of call-by-call. The router that connects the computer to the Internet for broadband connections serves as an intermediary for IP telephony. This is how IP telephony becomes call-by-call: Different IP telephony providers can be used for mobile communications, international calls or for individual destinations / individual phone numbers and the cheapest tariffs can be selected. In contrast to the call-by-call tariffs, which often change every hour, the connection prices usually remain constant over a longer period of time. In terms of mobility, IP telephony is more flexible than classic call-by-call. While call-by-call is only possible where a Telekom telephone connection is available, IP telephony only needs broadband access (independent of the provider).


In Germany, call-by-call has been possible for long-distance calls (cross-local network connections; connections to connections with different area codes) since Deutsche Telekom's telephone monopoly was lifted on January 1, 1998 ( see also telecommunications law ). In the first few years it was repeatedly the case that call-by-call providers had underestimated the influx of customers at peak usage times, failed to keep up with the expansion of capacity, or line capacities were deliberately tightly calculated ( overbooking ). The result was that the provider's connection network was overloaded ( lanes occupied ).

On April 25, 2003, after years of bitter resistance from the national regulatory bodies to EU Directive 98/61 / EC , Germany was the last EU country to also use this procedure for connections in the same local network (i.e. to connections with the same area code); previously, a regulatory loophole enabled call-by-call for connections in the local network via the 0190-0 special number alley. Due to a technical gap in Deutsche Telekom's switching computers, local calls could be made by dialing phone numbers in international format (e.g. 010xx-0049-30-12345678 for a phone number in Berlin) via some providers from 1998 until the gap was closed as part of the so-called carrier selection Phase II will be taught in July 2000.

In the past, it was possible to use call-by-call via alternative connection providers such as Arcor, NetCologne or Versatel , with Telekom being the only call-by-call provider available (Call-by-Call Selection T-Com), the also required registration. In July 2005, Telekom discontinued its call-by-call offer, so that today only call-through, call-back and sometimes 0900-call-by-call are possible via these connections.

Call-by-call Internet access, Internet-by-call

This call-by-call variant is used by Internet providers to provide customers with registration - free, narrowband dial -up Internet access via modem or ISDN . In this case one speaks of Internet-by-Call . For its use there are programs (called Software Least Cost Router ) that help the user to find and manage tariffs.

Price jumps and questionable business methods

Some providers were less interested in customer loyalty than in short-term profits: The dial-in numbers of the call-by-call provider were made known with inexpensive lure offers in order to settle drastically increased fees or unwanted club memberships after a certain time. In this context, billing cycles were also extended to up to ten minutes, which makes short calls extremely expensive. Well-known examples are PM2 Telecommunikation GmbH (01056 to 2009, then insolvency; from 2013 under the new name Arcinum GmbH ) and 3U Telecom GmbH (01078).

That is why the business methods of many companies in the area of ​​call-by-call and Internet-by-call regularly occupy consumer protection centers and courts, see also telecommunications companies in the criticism . In the case of Internet call-by-call, individual district courts have ruled on usury after price jumps to thirty-fold or hundred-fold. In 2008, the Wiesbaden Regional Court reduced an invoice from 01075 Telecom GmbH for a six-minute call to a Swiss special number from € 241.32 to € 3.50.

In order to create more cost transparency and security for callers despite the usual short-term price changes, other providers switched free price announcements at the beginning of the call signaling or guaranteed their tariffs for a certain period of time. With the amendment of the Telecommunications Act in May 2012 , the prices for call-by-call services must be announced at the beginning of the call. This rule does not apply to Internet-by-call.

However, due to a complaint by a call-by-call provider before the Federal Constitutional Court, the timely implementation of the tariff announcement was prevented. The obligation to announce the tariff should have been implemented after the signature of Federal President Joachim Gauck in May 2012. The delayed start of the statutory obligation to announce a tariff was therefore August 1, 2012. According to the TKG, every call-by-call provider has since had to switch a tariff announcement that provides information on all price components of the connection. This means that one-time charges or clocking must also be announced. Unlike previously usual, there must be no tariff changes while a call-by-call connection is in progress.

Role of Deutsche Telekom

Call-by-call calls are often billed to the Deutsche Telekom AG telephone bill . Deutsche Telekom AG has two roles in this:

This means that there is a constant conflict of interest : If, for example, a customer does not pay his bill in full, it often happens that Telekom satisfies itself 100% with the payment, while the other network operators (who are also its competitors ) do not have to satisfy sufficient rest. If a written instruction to Deutsche Telekom fails to satisfy its competitors first and then itself, then the competitors may block their connection network for the customer, although the customer has correctly followed the instructions of the alternative connection network operator to Deutsche Telekom instead of paying directly to the alternative network operator.

Until mid-2005, Deutsche Telekom was itself a provider of call-by-call to connections of alternative line operators.

Identify the current operator

By dialing the following numbers you will receive a free announcement with the information about which provider you are currently using for local or long-distance connections:

  • 0310 for long-distance connections
  • 0311 for local connections

However, if you first dial a call-by-call area code before these numbers, you will find out whether local or long-distance connections can be made via this area code.

Country comparison

Registration-free call-by-call and the billing of call-by-call connections via the telephone bill of the telephone connection provider are special features of the German fixed network market regulation that are not available in other countries.

The term call-by-call is not known in Great Britain, where the term “indirect access” (IA) is used instead, which corresponds to the German “registered call by call”. International low-cost area codes are called dial around or dial around service. While in other countries (for example Finland ) call-by-call can also be used via mobile phone , this is not possible in Germany.

Call-by-call compared with alternative provider selection options

Comparison with preselection

While with so-called call-by-call (CbC) a CbC number (VBNKZ, 010xy or 0100xy number) must be dialed before each telephone number to be dialed, this is not necessary with preselection . Although you are initially set to a network operator through the preselection, you can bypass this if necessary by using a different CbC number (technical override ).

If a call-by-call area code can be pre-selected without prior registration, this is referred to as open call-by-call or real call-by-call. In this case, the billing takes place with the bill of the connection operator (generally the Telekom). Some call-by-call providers only offer the use of their area code to customers who have previously registered ( closed call-by-call, registered call-by-call, call-by-call with registration ). Advantages are the ability of the provider to better assess line utilization and to be able to issue their own invoices , as well as the fact that customers can be notified of tariff changes. There are also connection network operators who offer both real call-by-call without registration and special call-by-call tariffs that require registration.

Legally, every connection established by means of a real, registration-free, open call-by-call is a separate contract, while with call-by-call with registration and preselection, a contract is concluded with the provider that all calls can be made from the agreed telephone connection Connections established via the network operator are billed at a specific tariff.

Comparison with call through or calling cards

Telephoning with calling cards and call through is often used as an option where call-by-call is no longer available due to a fixed connection change. With calling cards, a card is usually bought using the prepaid method and the connections are then made via 0800 numbers. The sale of calling cards is more expensive due to the commissions and is therefore usually less attractive for customers than call through. The caller usually has to authenticate himself by entering a PIN in order to be able to assign the call to a customer. In comparison, this procedure is more like a closed call-by-call.

With Callthrough, the provider is selected by dialing a chargeable number (without entering a PIN), which is later billed to your own provider. It is therefore more like an open call-by-call without registration. However, the caller already pays for dialing the destination number, even if the other party does not answer. In both cases, the main difference to the call-by-call procedure is that technically two connections are established, the connection to the provider and a second connection from the provider to the destination connection, which are interconnected when the connection is successful.

Alternative SIP connections with VoIP

With Internet telephony ( IP telephony ), the call is first routed through the Internet to the provider before it forwards it to the telephone network via a network gateway. This fact enables the caller to register with other VoIP providers in addition to the selected provider. Technically and organizationally, these are independent telephone connections. Booking your own telephone number is usually only offered as an option for cost reasons, as it is not required for outgoing calls.

In most common DSL routers , an integrated SIP adapter enables the connection of at least two analog telephones, which enables a configuration that incoming calls can be made via both connections and by plugging the telephone into one of these connections (or the connection multiple analog telephones) the provider can be selected for outgoing calls. Many SIP adapters (e.g. most FRITZ! Box models) also offer the option of freely assigning VoIP accounts and connections to one another. In connection with dialing rules, the device can be programmed in such a way that e.g. B. landline numbers, mobile phone connections and international calls are each made via a provider defined by dialing rule. Some VoIP providers offer tariffs tailored to this. B. enable mobile telephony particularly cheap.

A hardware-independent option is the installation of a softphone on the computer, which enables a configured provider to be selected before each call. Billing is possible using the prepaid or postpaid method , depending on the provider . Use without registration is excluded, as there is no organizational connection with a main provider who can take over the billing.

In addition, phone calls can be made between two subscribers directly over the Internet (i.e. without a telephone network), provided the caller knows the SIP address of the person called and external SIP requests are supported. It is more with internet services such as B. Skype comparable. This direct connection is possible with conventional telephones as long as the SIP adapter offers a telephone book whose entries can be accessed via speed dial from the telephone. However, since the standardized SIP protocol, which is compatible with other providers, is used, a free choice of provider is possible when calling over the telephone network.

Web links

Wiktionary: Call-by-Call  - explanations of meanings, word origins, synonyms, translations

Individual evidence

  3. Price jumps in Internet-by-call, legitimate or not .
  4. ^ Message from Teltarif
  5. Article on
  6. News on