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Fears have also been raised over how Brits can travel in and out of Germany after Brexit in the event of a no-deal because they won't have official residence status.

Around 7,000 Britons in the capital have submitted their details in the online registration system since it launched in January. But Berlin’s interior senate department told The Local there were around 18,000 British people in Berlin – and 11,000 still haven’t applied yet.

SEE ALSO: What you need to know about Berlin's Brexit registering process

The voluntary form, which as we reported was launched on January 3rd, offers British nationals living in Berlin the chance to apply for their residence status as the UK gets ready to leave the EU on March 29th, unless the deadline is extended.

From April onward, the Foreigners Office (Ausländerbehörde) plans to contact everyone who's registered online and invite them for an official appointment.

As Germany is a federal country, there are different ways that British people can apply for a permit.

SEE ALSO: Brits across Germany urged to apply for residence permit

Some states have issued letters asking residents to book an appointment with the Foreigners Office, while others are asking British people to fill in a form online. Officials have urged those who receive letters to follow the advice.

Questions raised over ease of travelling after no-deal

It came after an information evening was held in the capital on Monday, hosted by the Senate and the British Embassy.

During the event, questions were raised over how Brits will be affected in the event of a no-deal. If no withdrawal agreement is in place, there are concerns over if Brits who leave Germany to travel to another country will have problems getting back into Germany without a clear status.

SEE ALSO: No-deal Brexit: Which EU state offers the best (and worst) deal for Britons?

The Local has put questions surrounding these issues to the British Embassy and the German government.

Daniel Tetlow, co-founder of citizens’ rights group British in Germany, said a huge concern is that there is still not one clear outcome of Brexit so authorities trying to legislate have to deal with a number of possible scenarios.

“If there is a no-deal there were questions raised by the head of the Berlin Ausländerbehörde about the ease of returning to Germany,” he told The Local.

“This is something British in Germany is going to follow up with the German authorities to get more clarity for our members,” he said.

It will likely take months for Berlin authorities to process all the applications for residence permits. That’s because after people register online, the Foreigners Office has to invite everyone for an interview.

“It will take 6-9 months for people to all get their certificates which will confirm your new status in Germany,” said Tetlow.  “Without that the German Ausländerbehörde said you could come into problems getting back into Germany without a valid renewed residency status.”

SEE ALSO: Prepare for Brexit – the ultimate checklist for Brits in Germany

Although this is a possibility, Tetlow added that it’s important to remember that a no-deal is “still an unlikely outcome in four weeks’ time”.

'Fast-track system'

However, Tetlow said authorities confirmed that a fast track system for permits will be put in place for those people who need their status confirmed quickly, for example if their jobs depend on it or for medical reasons.

At the meeting the authorities said people who have lived in Germany for more than five years or people with family (for example someone who is married to a German) are likely to more easily receive residence status.

Those who have lived in Germany less than five years but are ‘economically active’ are likely to get a third country national residence permit.

Others, such as students or retired people who have been in Germany for a shorter time, will be looked at on a case by case basis.

Tetlow said the evening, which was a ticketed event attended by hundreds of Brits, showed the “incredible variety of people and the ways in which Brits have integrated into German society”.

“I was fielding such an amazing variety of questions from people who are going to be affected by the implications of a deal or a no deal,” he said. “For example, air stewards who are concerned about their rights to freedom of movement, crossing borders for their work.

“Retired people who haven’t been here for many years asking what’s going to happen to their pensions. It shows how 18,000 Brits in Berlin have integrated into German society in a massive variety of ways, which is very difficult to legislate for in every single case.”

It was clear once again that the message from German authorities was positive, Tetlow said. “They were supportive of our future in Berlin,” he said. “We will continue to be very welcome as British Europeans in Berlin.”

'Biggest worry is prospect of no-deal'

Tetlow added that the campaign group British in Germany “were pleased to see that the German authorities were starting to get more information out to UK citizens in Germany” and he said the group is “continuing to ask for more information to deal with the sense of unease and insecurity about our future lives here in Germany”.

He added that the biggest worry for members is the prospect of a no-deal. “This will throw up all sorts of unpredictable issues that will threaten the livelihoods of many UK citizens living in the EU,” he said.

Tetlow urged UK citizens living in Berlin to register, and for those living in other parts of Germany to contact their Foreigners Office to find out the registration procedures required.

“We would absolutely encourage all Brits living in Berlin to register before the 29th March, even though the chances of delay to Brexit are now quite high,” he said.