LarryE's point bears emphasis. Under NO CIRCUMSTANCES should an auto-number PK have ANY REAL-WORLD MEANING. To use it for audit continuity is contrary to its nature. An auto-number field has no business having any meaning. Well,... almost none. I sometimes use it as an after-the-fact "confirmation number" - but a random number or a hash-key could have been just as easily used in that context. The point is that the ONLY thing you CAN rely on regarding auto-numbers is UNIQUENESS. You cannot rely on CONTIGUITY. Actually, you cannot even rely on ORDER, since if you are sharing a back-end and two users come in to add records that include an auto-number PK and a time-stamp, it would be possible for the record to sort in two different orders based on that PK and the timestamp. The auto-number is defined when the new record gets dirty but the timestamp can be defined in a different order depending on the design of a form, particularly if it depends on a specific user action.