Every domestic corporation and foreign corporation (including a branch) engaged in business in Puerto Rico or with effectively connected income is required to file a corporation income tax return on or before the 15th day of the 4th month following the close of its taxable year. Corporations and partnerships taxed as pass-through entities are required to file the income tax return on or before the 15th day of the 3rd month following the close of its taxable year. The return should be filed with:

(For payment due)
Department of the Treasury
P.O. Box 9022501
San Juan, Puerto Rico 00902-2501

(For refund due)
Department of the Treasury
P.O. Box 50072
San Juan, Puerto Rico 00902-6272

The maximum marginal tax rate applicable to domestic corporations and foreign corporations engaged in a trade or business in Puerto Rico or with effectively connected income is 39%.

An extension of time for filing the return may be obtained if requested on or before the due date for filing the return. Such extension will not be granted for more than 90 days. Any tax due must be paid in full together with the request for extension.

A business operating in Puerto Rico may also be required to make the estimated tax payments. Payments of estimated tax are generally due on the 15th day of the 4th, 6th, 9th and 12th month of the taxable year and penalties are imposed for underpayment of the estimated tax.

If volume of business of a corporation is $3 million or more then the return must include audited financial statements in accordance with Generally Accepted Accounting Principles in the US (US GAAP) and Generally Accepted Auditing Standard (US GAAS).