The company initially founded Tele2 Russia, but later sold all its operations, later rebranding and changing the name to "t2".

Comvik later changed its name to become Comviq when the company got a GSM license in 1988 and started operating in 1992.

The Swipnet branding was phased out in 2014. International growth came in the form of acquisitions in Estonia, Lithuania, Latvia, Russia, and France.

[4] In November 2018, Tele2 was merged with telecom operator Com Hem, which delivered, among other things, TV, broadband and telephony.

[5] At the beginning of 2020, the streaming service Comhem Play+ was launched available to those who are not a customer at Com Hem and changed name to Tele2 Play in January 2022.

Focusing on own infrastructure-based operations which provide higher growth options and possibly better margins for the future.

Tele2 has terminated operations, activities, and holdings in the following countries: Austria, Belgium, Croatia, Denmark, Finland, France, Germany, Italy, Kazakhstan, Liechtenstein, Luxembourg, Netherlands, Norway, Portugal, Poland, Russia, Switzerland, and the United Kingdom.

Tele2 reportedly attempted to sell its German unit as well in 2007,[8] eventually the sale came through a management buyout in 2020.

[14] In a brief press statement on 11 November 2014, the Sweden-based telecoms group has confirmed that it plans to re-enter the Austrian mobile sector in the second half of 2015.

[22] In 2022, Tele2 acquired spectrum in the 3410-3800 MHz frequency band as part of a license to provide 5G [SM1] services.

They also used to operate alternative fixed line & internet services which they sold to Vivendi unit SFR for €350 million in 2007.

In 2005 it began to offer ADSL in large cities including Milan and Rome in unbundling, and then quickly extended the service to numerous other areas of Italy.

[32] Tele2 operates a nationwide mobile network in Lithuania, including 5G services in the 700 MHz and 3.6 GHz bands.

Tele2 operated as a 2G, 3G and 4G MVNO on the mobile network of T-Mobile NL and in the fourth quarter of 2015 launched the world's first 4G-only MNO in the Netherlands with nearly 850,000 customers in addition to fixed network triple play services, serving over one million customers in total.

Tele2 purchased Versatel in the Netherlands in mid-2005 which allowed it to move away from carrier select services via KPN and onto own infrastructure.

When the Swedish Post and Telecom Authority awarded four licenses for the 3G UMTS mobile networks in December 2001, Tele2 was among the winners.

A similar company, Net4Mobility, was formed in 2009 between Tele2 and Telenor Sverige for the purpose of building a joint 4G LTE network.

The 4G product was officially launched on 15 November 2010 and in 2023, Tele2's 4G network today covers 99.9% of the Swedish population.

[41] In a Court of Appeal case with a judgment published on 21 January 2009, companies in the Tele2 group were successful in a claim for damages against Post Office Ltd. for wrongful termination of a contract concerning the sale and promotion of telephone cards.

The Post Office continued to fulfil its obligations under the contract until they sought to terminate it in December 2004, some 11 months after the breach.

The Appeal Court held that the waiver clause in the contract, which stated that In no event shall any delay, neglect or forbearance on the part of any party in enforcing (in whole or in part) any provision of this Agreement be or be deemed to be a waiver thereof or a waiver of any other provision or shall in any way prejudice any right of that party under this Agreement could not be relied upon where the party entitled to enforce the term had not merely delayed action but had positively "elected" to continue to fulfil its contractual obligations, as evidenced by its behaviour.

Tele2 has an option to buy the remaining 49% of Mobile Telecom-Service LLP within 5 years after the contract was closed.

[46][47] During its operation in the United Kingdom[48] and Italy,[49] Tele2 was criticised for using the practice of telephone slamming (changing consumer's residential phone line over to a new provider without their consent).

[50] The company was also criticised for faking a meteorite landing in Latvia in October 2009, as a result of which the Latvian government cancelled its contract with Tele2.

BITE, its fastest growing Lithuanian competitor won its case through the competition authority.

[54] It has grown a reputation for aggressive market practice and has been involved in court cases and legal criticisms in several other countries, including Poland.