In Access, you can change the field size that is empty or already has data. If the field size does not contain data: When you change field size, the value of the new data values is limited for the field. For number fields, the field size determines how much disk space Access uses for each value of the field, and for the text fields, the size determines the maximum amount of disk space that Access allows for each value of the field. If the fields contain data: When the field size is changed, Access truncates all field size that exceeds the specified field size and limits the value of the size of the new data values for the field.