As a US LLC, you have the obligation, at the end of the year, to report to the IRS any person or company that you paid (in most cases) more than $600 during the year. In addition, depending on the situation, you could be required to without up to 30% of the amount owned as tax.The first step is collecting a W9 (from a US freelancer) or a W8 (from a foreign freelancer). After that, you are able to pay them, deducting any withholding tax.At the end of the year, for each W9 worker you paid, you must send them a 1099 form (either by physical mail or electronically, the recipient must be given the choice). For W8 workers, you must send them a 1042 form. Your LLC must also file a record with the IRS that shows all the payments made to W9 and W8 workers/companies. The deadline for filing this for W9s is the last day of January. The deadline for filing this for W8s is the last day of March.If you have a lot of these kinds of workers, the can obviously get quite cumbersome. Payment Rails is a great software to help you automate this whole process of collecting and sending forms, including filing with the IRS (Full Disclosure: I work for Payment Rails).