You can disable a custom profile field you no longer need.
Caution: Disabling a custom profile field permanently deletes all existing user data associated with that field. This action can't be undone. Before disabling, check that the field isn't needed for users, report filtering, or an organisational segment.
Tip: Before disabling a field, download the user data containing that field's information. This gives you a backup on your device in case you need it later.
Step-by-step instructions
Go to Settings.
In the USERS section, click User profile fields to show the list of available custom profile fields.
Scroll through the list to find the custom profile field you want to disable.
Clear the check box on the left of the field name.
Read the confirmation message and, if you're sure, click OK.
Click Save Changes.
If you're looking to add a field, see How do I create a custom profile field?
FAQ
I disabled a field but want to re-enable it. Will historical data still be available?
I disabled a field but want to re-enable it. Will historical data still be available?
No. Once a field is disabled, all associated data is permanently deleted and can't be retrieved. Before disabling a field, download the user data containing that field's information so you have a backup on your device in case you need it later.
I no longer need a custom field but don't want to lose the data. What should I do?
I no longer need a custom field but don't want to lose the data. What should I do?
You can mark the field as non-required and hidden from users. This keeps the historical data intact, but users are no longer prompted to fill out the field.