There are more than 5,000 residents' registration offices (“Meldeamt” or ”Bürgeramt”) in Germany, and they are tasked with numerous services. They take care of the registrations, move-outs and address changes, as well as issuing personal and children ID cards, etc. Besides, the residents' registration offices should also provide information from their database if a person makes an inquiry for a registry entry or "Resident's Registration Entry Request" ("EMA-Anfrage"). Such a request may be useful if you are searching for friends or family members, or in case you want to find a customer who has moved or your debtors.
Private providers also offer this service, but often demand money in return. On melderegister-auskunft.de you can find a list of the reliable private providers. The resident's registration offices also charge a fee, which varies from one municipality to another. Even if the person you are looking for is not found as a result of their service, you still have to pay the fee. The processing time also varies from one office to another. Sometimes it takes only a few days, but it also may take several weeks at times.