Abound was a US tax-compliance API company for platforms, marketplaces and fintechs serving the 1099 economy. Its v4 REST API covered the full information-return lifecycle: collecting Form W-9, W-8BEN and W-8BEN-E from payees, running real-time TIN verification against the IRS, then generating, filing, correcting, voiding and physically mailing… - View it on GitHub