Why would the address on the contract matter? If the contract lists 'ABC' as their address, you still need to serve papers to their registered office which may have always been XYZ, or may have changed after the contract was signed - so in any case you have to ignore the address on the form and use the official one that you look up from the registry.
The only case where I've seen address used as a disambiguator is when treating multiple private individuals with the same name, but in that case also you want some official ID, not the address which may change frequently (and may contain a different John Smith than the one who lived there a year ago).
The only case where I've seen address used as a disambiguator is when treating multiple private individuals with the same name, but in that case also you want some official ID, not the address which may change frequently (and may contain a different John Smith than the one who lived there a year ago).