Dear Ms. Nicholls,
Thank you for posting your request on History Hub!
We searched the National Archives Catalog and located the series titled Records Relating to Membership in the Nationalsozialistische Deutsche Arbeiterpartei (NSDAP) in the National Archives Collection of Foreign Records Seized (Record Group 242) that are available as Microfilm Publication A3340. The NSDAP membership records, sometimes collectively known as the "Master File," consist of central and special registries and card indexes. Within the “Master File” included are Anträge, Ortsgruppenkartei, Zentralkartei, Party Census (Berlin), Warnkartei, NSDAP Schwarze Listen, and Mitglieder-Sammelstelle der NSDAP. These files record essential biographical and Party membership data for each individual. For access to these microfilmed records, please contact the National Archives at College Park - Textual Reference (RDT2) via email at firstname.lastname@example.org.
Please note that that due to the COVID-19 pandemic and pursuant to guidance received from the Office of Management and Budget (OMB), NARA has adjusted its normal operations to balance the need of completing its mission-critical work while also adhering to the recommended social distancing for the safety of NARA staff. As a result of this re-prioritization of activities, you may experience a delay in receiving an initial acknowledgement as well as a substantive response to your reference request from RDT2. We apologize for this inconvenience and appreciate your understanding and patience.
We hope this is helpful. Best of luck with your research!