&Thomas.Baumgart; &Thomas.Baumgart.mail;
&Jack.H.Ostroff; &Jack.H.Ostroff.mail;
2024-12-01
5.2.0

# File Formats

Unless you choose to use a relational database, &kmymoney; will store all your financial information in a file. Most commonly, the file name will end in `.kmy`. Also, when you launch &kmymoney;, unless you use a command line option that tells it not to do so, it will open the last file it had open. However, it is important to know that there is actually more than one type of file &kmymoney; can use to hold your financial data.

This chapter describes the file formats in which &kmymoney; can store its data in permanent form. It also discusses backing up your data.

## Data File formats

In general, &kmymoney; stores its information in form of an &XML; document. Depending on the actual format, which is set in &kmymoney;'s configuration, this &XML; document will be written:

- as a plain text file, encoded in UTF-8,

- as a compressed file, using GZIP compression,

- as an encrypted file, using GPG encryption, or

- as an anonymous plain text file, encoded in UTF-8 but with all your personal data scrambled.

Each of these is described in more detail in the following sections.

### Plain text file

This is the most space consuming format supported, as no compression is performed. It is not intended for normal use, and is provided to support debugging purposes and the capability to modify the file manually. If you end a filename in `.xml`, the file will be stored in this format.

Manual modification of the file is not recommended to the normal user, and should only be performed if the internal working of &kmymoney; is fully understood or if instructions from the developers tell you what to do. Don't blame the &kmymoney; developers if you damage or destroy your data: You have been warned!

### GZIP-compressed file

This is the normal format used by &kmymoney; when you store a file with the extension `.kmy`.

If encryption has been selected in the configuration, the file will be stored encrypted, as described in the next section.

If you want to look at the contents of a GZIP compressed file, rename it to a filename ending in `.gz` (⪚, rename `myfinances.kmy` to `myfinances.kmy.gz`), then use `gunzip` to uncompress the file and look at it. You don't have to compress it before loading it into &kmymoney; the next time, because &kmymoney; can read the uncompressed data as well. Nevertheless, if you save it thereafter, it will be saved compressed again. Use the `.xml` extension to write it in uncompressed format.

### GPG-encrypted file

Using the GPG-encrypted file format is a very secure method of storing your personal finance data on your storage device. When &kmymoney; has been instructed through the settings dialog to store your data encrypted, it will cipher the data using GPG and the key you provided before actually storing it. When opening an encrypted file, you have to provide the passphrase necessary to open your keyring. The encrypted file itself will be stored in GPG's &ASCII; armored format.

When using GPG encryption, GPG also compresses the file using gzip, so no extra compression is necessary.

#### GPG-Keys

If you have not done so already for mail encryption, you need to generate a key-pair in order to use the GPG encryption feature of &kmymoney;. Also, GPG must be installed on your system.

The details about how to generate a key-pair and how to take care of it are beyond the scope of this document. A Mini Howto on this subject can be found at https://www.gnupg.org/documentation/howtos.en.html. The web sites of most &Linux; distributions also contain instructions on using GPG in that distribution.

#### Setting the keys in &kmymoney;

On the encryption page of the settings dialog, there is a dropdown list where you can select the key that should be used for encryption and decryption. Additionally, there is a field where you can enter the key-id of a key not in the listbox. You can use either the key-id, the email address associated with this key, or any other valid GPG key identification as the value for this field. When you enter the key-id, &kmymoney; will check its validity and display a green LED icon in the dialog if a key is found.

Make sure you have both the public and the private key for this id. If you do not own the private key for the id entered, you will not be able to open the file again.

#### The &kmymoney; recovery key

Also on this page of the settings dialog you have the choice of selecting supplemental encryption with the &kmymoney; recovery key. This option is available to you if that key is stored in your GPG keyring. Selecting this option will allow you to recover your data even in the case you lose your own private key. This is possible because the data is not only encrypted for your own key, but also for the &kmymoney; recovery key. This key is only available to selected &kmymoney; developers (at the time of writing only to the author.) As of the May, 2024, the recovery key is set to expire on 7 January 2025.

Under normal circumstances, you will open/save/close your file as usual. In the abnormal case of loss of your key, you have the chance to contact one of the developers who has access to the &kmymoney; recover key and request help to recover your data. You may contact the developers via email to the &kmymoney; developer mailing list at &devlist;.

To get the recovery key, go to The KMyMoney recovery key page of the &kmymoney; web site. Copy and save the PGP PUBLIC KEY BLOCK (including the BEGIN and END lines) to a text file and then import it with gpg.

Remember that the developer can only help recover your data file if you actually do encrypt it with the recovery key, in addition to your own key.

### Anonymous file

This format is not intended to be used for normal data storage. It is supported so that in case of a problem, you can supply the &kmymoney; development team with your file without disclosing any of the confidential details in your financial data. For example, it changes institution, account, payee, and category names to strings such as "I000001" and "A000001"; it makes similar changes to all data such as account numbers, and it also randomly changes the amounts of transactions.

If instructed by the developers, use the Save as... menu item to store your data in anonymous format by selecting `Anonymous files` as the filter. This also changes the file extension to `.anon.xml`.

To verify that your problem still exists, reload this anonymized file and try to duplicate your problem. If the problem is still present, send the file to the developer mailing list at &devlist; for further investigation. If the problem does not show ... well, I don't want to think about this scenario right now.

### Data file locations

All of the above file types can be stored on a local hard drive, a removable device such as a usb thumb drive, or a network location. Depending on your Operating System, a remote location may need to be mapped or mounted prior to use.

Limitation on Windows

On &Windows;, in order to use a network or remote file location, that mapped location must be mapped to a drive letter.

## Backup

We will not attempt here to convince you that making backup copies of your data is an extremely good idea; hopefully you are already convinced of that. This section describes three ways to do this, and you can use any one, two, or even all three of them. Note that this is about backing up a data file; if you use an SQL backend to store your data, see the documentation for that database system for instructions on making backups.

### Backup file location

If you need a backup copy of your data to confirm some aspect of your finances at a previous point in time, or to revert to an earlier state, such as to undo importing a lot of data to the wrong account, it doesn't matter whether the backup copy is local or stored elsewhere, such as on an attached network drive. However, if you need a backup to recover from loss of data if you disk drive failed, for example, it is essential that the backup is not on the same drive as your primary data file. In case of a larger disaster, such as a house fire, you would need a backup copy stored in a fireproof safe or at a physically different location. Please keep this in mind as you establish your backup strategy.

### Autosave

&kmymoney; has the ability to automatically save a copy of your data file at regular intervals. It can also do so on closing the program, if the data has changed. This behavior can be configured on the &kmymoney; configuration dialog, General section, Global tab.

### File copy

Unless you are using SQL storage, your data may be compressed, and it may be encrypted, but is kept in a regular file. Whenever you save your data with the File Save menu item, it writes all your data to a file, replacing the previous version. The most straightforward way of backing up your data is by making a copy of that file. A single copy can even have the same file name if it is in a different folder than your original file, but if you are going to keep multiple copies, it makes sense to include some version of the current date and time in each file name. You can save these to a network drive, or to a USB storage device, or even to an optical device. The primary downside of this method is that you need to keep track of all the backups, but it does provide the most flexibility.

### Backup command

To make things a bit easier, you can select the File Backup menu item.

file backup
file backup

When you click OK &kmymoney; will create a copy of your data file, with the date (formatted as YYYY-MM-DD) appended to the name. Note that this means only one backup per day can be created by this method. If you have already created a backup on the same day, &kmymoney; will ask if you want to replace the previous backup or cancel.

&kmymoney; will save this file to the directory specified in the Mount Point field. You can either manually type the full path to the directory or click Choose... and navigate to it using the file browser. The directory can be on a local storage device or it can be a network folder.

If the specified directory is actually a mount point for a storage device that is not always mounted, you can check the Mount this directory before backing up checkbox. Do not use this for a regular network file share which is always mounted.