I used to work for a division of State Farm insurance which ran into some similar issues with addresses on or close to state lines. Insurance is also one of those businesses that's very particular about location, as we were only approved to do business in certain states.
The solution we ended up going with was to use the free Tiger shape files from the US Census (https://www.census.gov/geographies/mapping-files/time-series...), which enabled us to statically "lock" our geocordinates. Apart from filing our approach and getting it approved, the logic was that we could always point back to it being a government database if there was ever a problem.
The solution we ended up going with was to use the free Tiger shape files from the US Census (https://www.census.gov/geographies/mapping-files/time-series...), which enabled us to statically "lock" our geocordinates. Apart from filing our approach and getting it approved, the logic was that we could always point back to it being a government database if there was ever a problem.