Germany does not have a fixed telephone number length or format. Since 2010, new land line telephone numbers have a fixed length of 11 digits, but area codes remain variable.
Germany's system is known as an open telephone numbering plan, which means that some subscribers who have had their service for a long time have telephone numbers with as few as two digits, plus an area code. This system is designed for flexibility, as it allows people to add an ever-increasing number of phone numbers within a given geographic area.
Cellular phones have area codes outside the geographic area code system, and they generally consist of ten or eleven digits.