The data in the ID card must always be up to date, otherwise it becomes invalid. In addition, as a German citizen, you are required to have an identity card from the age of 16.
You are therefore obliged to notify the Bürgeramt of the following:

• Name changes
• if you have lost your identity card
• if your identity card has been stolen
• if you have recovered your identity card after reporting it as lost
• Note: You can also report the loss and theft of your identity card to the police.

There are 2 exceptions:

• If your address or height changes, your ID card remains valid.
• If you do not comply with the obligation to report a new address within Germany, you are acting irregularly.