If you need additional expense fields or extra fields in the users' details, you can create them in 'Settings' - 'Company Settings' - 'Custom fields'.
For manual creation you click on the green button 'Add custom field', to create several fields in one batch or to upload the custom field values you can use the relevant CSV-template via the other two buttons.
You can set the additional expense field per expense type and limit it to roles or link it to trips. If you wish you can even link your own custom fields to certain projects, so that depending on the choice of project only relevant fields will appear for the user. If you want more information on the employees to be shown in the accounting report, you can create an extra field in the users' details as well.
In both cases you can choose to work with a free text field or with predefined values. When selecting 'predefined values' an extra option will appear on top of your screen to create a reporting filter from this field.