A customer, job or change cannot be removed

Steps

Read which record still refers to the item you are trying to remove.
Keep a customer that has jobs or estimates. Archive an old job that has financial history.
Invoices with recorded payments and changes linked to invoices are protected.
If you are correcting a mistake, make a backup and correct the related records deliberately rather than deleting a chain of legitimate history.
If an item was already removed in a previous action, return to the register and refresh the view.

Historical invoices and payments remain connected. Find archived jobs with Jobs & profit → Archived.

This article covers these on-screen help codes:

Report a protection error if no related records exist and the item is still shown in the register.