When you import a data file, QuickBooks detects whether a record already
exists that matches a record you're trying to import. When a duplicate
record is detected, QuickBooks offers you three options.
Keep existing data and discard import data
Replace existing data with import data, ignoring blank
Replace existing data with import data, including blank
Click Apply to apply the preference to the current record.
Click Apply to All to apply the preference to all records.