The TaxJar PHP SDK by TaxJar integrates sales tax features into online business applications. Installation, usage, and authentication included. If code is correct, users should be able to report taxes using automated methods.
ValueAppeal is a service to help U.S. homeowners appeal the assessed value of their home. Over-assessed property results in taxes that are higher than they should be. This means that homeowners may be over-paying their taxes by anywhere from $500 to $1,000 or more. I wouldn’t mind keeping an extra $1,000 of my money per year going forward and I bet the same goes for most of America. If you have a website focused on real estate (did anyone mention this to Zillow?) the ValueAppeal API could augment it with compelling information.