As an admin you can edit all created custom fields via the settings in the central management at any time.
Edit custom fields
To edit a custom field click on the drop-down menu of the field you want to edit and select the item “Edit custom field”.
In the overview you find all basic settings, as well as the allocation. You can make changes in certain settings.
All settings that specify the field but do not change the function of it, can be edited.
This means that the label and field description as well as the options can be adjusted. For formula fields, the formula itself or the units can be changed.
Also the allocation to projects can be changed subsequently. As an admin you can determine whether the custom field should be used globally or in a specific project.
The function of the field can not be changed after the creation of the field, so that a new field would have to be created, which could then be used as a calculation field instead of a number field, for example.
Effects of the editing
Please note, that changes of a field always act globally. For example, if a formula field serves for setting the number of hours off against the costs, these changes have an impact on the whole budget management of a project.