Crosscheck data between two databases

Needing to check my unregistered voter database against the county's voter registration database. Roughly 25% of my list is in fact registered, but there are slight variations in the information on first names or street addresses due to nicknames (i.e. Bob instead of Robert or input errors of street numbers). Tables were joined using access, cross checking the last name, first name and street number. Separately, the phone numbers were as well. Provider must use their logic to check for similarities enough to show that my records are or are not registered. Will create a priority list so work can be completed in order. Budget is $270. Completion time is 10 days, no more. I will forward a link to download the county database and I will upload the list of my unregistered voters.