It doesn’t matter if your old passport has expired and a new one has been issued; your settlement permit or EU permanent residence permit remains valid in Germany.
There are different websites publishing conflicting information on whether to apply for a new residence permit when you receive a new passport or not. However, we ask you to check with your local citizen’s office for a more concrete answer.
In general, your settlement permit or EU permanent residence permit is still valid in Germany even if your previous passport has expired and you have already received a new passport. For re-entering Germany, you just need to show your old and new passport together and your previous settlement permit at the border control.
Before traveling to another country, however, we recommend you to check with your respective local authorities or the embassy/consulate of your country about the entry formalities in good time before you leave Germany.
Your temporary residence permit ends at the latest with the validity of your passport. If you have not yet received the extension of your residence permit, you need a fictional certificate. When traveling abroad, carry all documents proving your right of residence in Germany with you. This also applies to trips to another Schengen country.