# File and data format
Your administration is stored in a single **.openbook** file.
This is a zip file with the following format:
administration.openbook/
├── info.xml
├── C/
│ ├── 1.xml
├── E/
│ ├── 2.xml
├── I/
│ ├── 3.xml
├── T/
│ ├── 4.xml
├── P/
│ ├── 5.xml
├── documents/
│ ├── invoice_1.pdf
│ ├── invoice_2.pdf
**info.xml** : contains all company settings and data.
**documents/** : Contains all documents from which invoices have been generated.
**C/** : Contacts.
**E/** : Cost centers.
**I/** : Invoices.
**T/** : Tax rates.
**P/** : Projects.