No, not anymore! Only basic protection measures still apply, i.e. mandatory masks in public transport and in healthcare facilities (such as hospitals and nursing homes). For certain areas, such as schools, mandatory testing remains. 

According to the Occupational Health and Safety Ordinance of March 20, 2022, which remains in force until May 25, 2022, employees must still be protected against work-related infections by basic protective measures. Please check which occupational safety measures are required for your company. Accordingly, we recommend providing your staff with free rapid tests and masks. The legal basis for checking staff vaccination and testing records no longer applies. You can find further information on occupational infection control at the Website of the Federal Ministry of Labor and Social Affairs.

Summary: 

There will no longer be a legal basis for requesting the vaccination status or test certificate of guests after April 1st. For reasons of data protection, it will also not be possible to query the vaccination status or proof of testing on the basis of the house rules..
In the interest of everyone's health, we recommend continuing to ask your guests to get tested before visiting and to refrain from visiting if they have symptoms. 

Background Information: 

For data protection reasons, there is much to suggest that (without a specific legal basis) querying the vaccination status of guests or requesting a negative test is now inadmissible, as there is no purpose for collecting such data from guests anymore. The vaccination or recovered status of a person belongs to the sensitive and particularly protected health data, which in principle may not be queried or collected and stored or processed in any other way (Article 9(1) of the General Data Protection Regulation (GDPR)). However, the GDPR also allows exceptions to this, for example for reasons of public interest in the area of public health (Article 9(2) GDPR).

We recommend to ask your guests to take a free rapid test before the club visit and to refrain from coming if they have any symptoms. Please also check at the door if people show covid symptoms and ask if they have felt sick recently. 

In addition, the proper operation of a suitable ventilation system protects against the concentration of aerosols and thus reduces the risk of infection. 

To protect your staff provide free rapid tests and masks for each work assignment. Please also note the still applicable occupational health and safety regulation.

Summary:

The Berlin Senate currently sees no basis for the so-called hotspot regulation in the Infection Protection Act. For example it could again be used to order the presentation of 3G proof when entering certain facilities and companies. Limits on the number of people at events or contact restrictions are no longer envisaged. If the situation gets worse, the Senate can decide on this again. Until then, only the basic protective measures will apply.

Background Information: 

From April 01st, there are only a few so-called "basic protection measures" which do not affect the club cultural scene. In addition to the basic protection measures, there is the possibility of "hotspot regulations".  Accordingly, hotspots are areas in which "there is a concrete danger of a dynamically spreading infection situation". Such a danger exists, for example, when a dangerous viral variant spreads or when infection figures rise sharply and at the same time hospitals are threatened with overcrowding. The Berlin Senate must determine the existence of a corresponding situation by resolution. How broadly the hotspot is defined should be flexible to implement: it can be limited to a single district or encompass an entire state. To date, no consultation has taken place in the Berlin state government on possible hotspot regulations (as of March 31st).

Summary:

The existing data collections (e.g. in the form of lists) must be deleted, as the purpose of the collection no longer exists due to the discontinuation of the legal regulation.

Background Information:

The basis for the data processing and the obligation to provide evidence was § 28b III IfSchG. The principle of purpose limitation applies to deletion. Whether the purpose has ceased to exist or not cannot be determined completely conclusively. Bettina Gayk, State Commissioner for Data Protection in Nordrhein-Westfalen opine that the data should now be deleted.
From the press release of the State Commissioner for Data Protection in Nordrhein-Westfalen dated 23.03.2022, the following is stated:  „Mit der Änderung des Infektionsschutzgesetztes vom 20. März 2022 entfällt die Verpflichtung zum Nachweis der Impfung, der Genesung oder der Negativ-Testung (3G-Nachweis) am Arbeitsplatz. „Die aktuellen Lockerungen im Rahmen des Infektionsschutzgesetzes des Bundes nehme ich zum Anlass, um auf Fristen für die Löschung der gesammelten Daten hinzuweisen: Die von den Arbeitgeber*innen erhobenen Daten müssen spätestens sechs Monate nach Erhebung vernichtet oder gelöscht werden. Da die Rechtsgrundlage entfallen ist, gehen wir davon aus, dass die Speicherung regelmäßig nicht mehr erforderlich ist und die Daten schon jetzt gelöscht werden sollten.“
In general, companies must delete personal data when it is no longer necessary for the purposes for which it was collected or otherwise processed. The purpose of data processing thus determines the permissible duration of storage of the processed data. This so-called purpose limitation principle is one of the key principles of European data protection. Companies may only collect personal data for predetermined, explicit and legitimate purposes. In addition, you may not further process this data in a way that is incompatible with the original purposes (Art. 5(1)(b) DSGVO). At the latest, when personal data is no longer necessary for the purposes for which it is processed, the company must delete this data.