The EU and the United Kingdom have agreed on a free trade agreement.

Especially relevant for the Limited in Germany could be the non-discrimination clause (national treatment) included in the free trade agreement. This can be found on page 101 of the German version of the agreement and reads as follows:

Article SERVIN.2.3: National Treatment

1. Each Party shall accord to investors of the other Party and covered enterprises treatment no less favorable than the treatment it accords to its own investors and their enterprises in like situations with respect to the establishment and operation in its territory. 

2. The treatment granted by a Party under paragraph 1 means ...

On February 20, 2019, the Finance Committee presented its recommendation for approval and report on the draft legislation for the Brexit Tax Accompaniment Law. The draft includes, among other things, an amendment to § 12 of the Corporation Tax Act. A new paragraph 4 is to be added, which reads as follows:

"(4) A corporation with unlimited tax liability located in the United Kingdom of Great Britain and Northern Ireland shall continue to have the business assets attributed to it that were attributed to it before the withdrawal from the European Union."

According to the literal wording of this provision, this would be limited to limited liability companies that were established before Brexit. However, the explanation to the amendment explicitly references the supreme court jurisprudence of the Federal Finance Court on the type comparison for companies from third countries (judgments of June 23, 1992, BStBl II p. 972, and of September 8, 2010, BStBl II 2013 p. 186), suggesting that this regulation might be interpreted broadly and that the last half-sentence of § 12 para. 4 KStG should be understood as clarifying that Brexit itself is not a triggering event.