Source: https://www.vonengelhardt.com/en/brexit-and-immigration-germany
Timestamp: 2019-04-23 00:34:16+00:00

Document:
The people's voice in majority said "out". So be it; this is nothing but a democratic decision. It is also normal, that people cry out loud if their opinion is not followed. How will this effect Brits in Germany right now? Will they be kicked out? May they stay? I want to briefly discuss the legal consequences for immigration of the BREXIT – shortly before the "divorce" is final. What is now to be done? How do I maintain a legal status? What rules will be applicable for future relocations?
Before the BREXIT really kicks in, it is "life as usual" for all British residents and their non-European direct family members. Since the freedom of movement only ends, when BREXIT comes into force, your residential status has not ended just because Ms. May officially applied "for divorce". You are not yet in Germany but prefer to be here? What is keeping you back? If you do not relocate before BREXIT takes effect, you will have to stand in line as all the "other" nationals.
Britain's Prime Minister, Ms. May, has now formally given notice to the European Commission (art. 50 TFEU). In spite of any tug-of-war of "to brexit or not to brexit", the two-year period will end with the expiration of March 2019. Within this period, the European Union and UK have to come to a resolution on how the divorce will be realized. If nothing is negotiated inside that period, then EU membership automatically expires. Until then, it is life as usual – seen from immigration perspective. Assuming no resolution between UK and EU will be achieved then it is a full stop!
Britons and their non-European family members will automatically lose their freedom of movement and so any legal residential status as soon as BREXIT comes into effect. They no longer belong to the European Union. At first glance, this sounds harsh but there is a solution at hand. The persons now here on a temporary as well as a permanent status will maintain their status – upon application. As BREXIT deadline draws near, the question comes up, will BREXIT be soft or hard or at all. In the case of a hard BREXIT, Britons will immediately need a residence permit. Pursuant to §11 III FreizügG these persons living here previously shall retain their legal status – as is. However, you need to apply for this at your local immigration office.
Persons living here for more than five years will continue with permanent residency, a.k.a. settlement permit. Such British subjects having residence for less than five years will be treated as if they had had a (temporary) residence permit all along. So far, there is no reason to worry. However, the devil is in the details... Do not forget, we are talking of an event to happen on March 29, 2019!
So much to the consequences as they are – now. Pursuant to §7 I 2 AufenthG, those persons on a temporary status can expect to continue as a normal third-country national on grounds reflecting their reason to be here. Everybody will have some sort of concept / purpose of being in Germany and not anywhere else in the world. A student will receive a permit to study at the university pursuant to §16 I AufenthG; an employee pursuant to §18 AufenthG, and a person in business based on §21 AufenthG. Latest when a renewal is due, it can be assumed that they will be treated as a “normal” third country national. This means you are continuing with a head start. It is expected that you will have to show that you meet the requirements as every other non-European has to for your individual reason to be here.
Britons having had “permanent EU status” will change from §4a FreizgG to §9 AufenthG – maintaining permanent residency. The difference between both kinds of permanent status is only hidden. The most important difference will be in the time of permitted absence without jeopardizing one's permanent status. Pursuant to §4a VIII FreizgG, Europeans are allowed to be outside of Germany temporarily for two consecutive years. Third country nationals only have six consecutive months (§51 I no. 7 AufenthG) grace – both only for temporary purposes. So, if you have left for good then you are out for good. However, such persons living now under a settlement permit, will not lose their status if they have been in for 15 years when their financial livelihood (= basic need, health insurance, and accommodation) and no reasons for expulsion exist (§51 II AufenthG).
Another major difference between “normal” and “European” foreigner lies in the status quality. Europeans conceptually have the right to be in Germany. The threshold to end a European's residence is very high the longer this person lives in Germany. In contrast to that “normal” foreigners have to combat the authority to remain in Germany.
On October 29, 2018, the German Federal Government published the draft bill for the BREXIT transition period in regards to naturalization as German citizenship. British citizens that apply for naturalization in Germany before the end of the transition period will be able to retain their British citizenship based on §25 II 1 Citizenship Act. This transitional period lasts from March 2019 until December 31, 2020. This means applications for naturalization submitted until December 31st, 2020 are privileged in so far that British citizenship does not have to be renounced.
How to Prepare for after the BREXIT?
get Letters Of Interest from Germany-based business partners, when freelancing or self-employed, start working on your business plan.
Parallel to that apply for your new status in Berlin via the webpage "Departure of the United Kingdom from the European Union (Brexit)". If you live somewhere else in Germany, click this sentence to find your local immigration office.
N.B. This update reflects the legal situation as of March 05, 2019. Further updates will follow shortly after they are issued as law.

References: §11
 §7
 §16
 §18
 §21
 §4
 §9
 §4
 §25