Hi Bill,
I think you want to update the location with the ID, but you reference to city.
You provide minimal info, but i think you need an extra field City in MK to lookup the City in ServiceLocation and update LocationID in the MK table, and only if Location in MK is NULL.

Thanks marc.  You're right.   For not I'm converting a city to a record id from another table which is successfully going into city.  During the building process I'm just adding from spreadsheet.
The thing that has me perplexed is that I'm not writing to the ID field but am getting a key field violation when I try.  You'll notice that "locationID" is coming from servicelocations to translate the city field to an ID.
I'm expecting autonumber to automatically create an ID when I run the append query for the new records.  The location in mk will never be null.

I have viewed the query and the data is correct as shown below.  Yes this is just two records, but in the future there may be more to import.  I'm trying to make this as automated as possible to futureproof it all.  The intended user is happy with his spreadsheets until I show him the solution I'm building.