Deportation requires that the authorities send the person concerned a written decision beforehand. This is done either by the responsible immigration office or - if an asylum application had previously been made - by the Federal Office for Migration and Refugees. As a rule, the authority decides at the same time in the decision that the person may not return for a certain time after the deportation and may no longer be in Germany (so-called entry and residence ban). The person concerned has the option of having the authority's decision reviewed by the court within a period of time, which may vary from one week to one month, depending on the case. If the person misses the deadline or is unsuccessful in court, there is a risk of deportation from this point on.