Saint Vincent and the Grenadines is a sovereign island nation located in the Lesser Antilles in the Caribbean Sea, and its taxation system is governed by the Income Tax Act and the Value Added Tax (VAT) Act.

Corporate taxation in Saint Vincent and the Grenadines is levied on resident companies at a flat rate of 30% on their worldwide income. Non-resident companies are taxed only on income generated within the country. There are no capital gains or withholding taxes in Saint Vincent and the Grenadines. Companies must file an annual tax return and pay their taxes by the end of March of the following year.

Personal taxation in Saint Vincent and the Grenadines is also based on a progressive tax rate system ranging from 10% to 32.5% on all income earned by residents. There are no taxes on capital gains, inheritance, or gifts. However, individuals who earn more than EC$5,000 (Eastern Caribbean dollars) per year are required to pay a social security contribution of 4.5% to 6.5%, depending on their income level. Individuals must file an annual tax return and pay their taxes by the end of March of the following year.

In addition to income tax, Saint Vincent and the Grenadines also has a Value Added Tax (VAT) of 16%, which is levied on most goods and services. Registered businesses are required to collect VAT from their customers and remit it to the government. VAT returns and payments are due monthly or quarterly, depending on the size of the business.

Taxpayers in Saint Vincent and the Grenadines can file their tax returns and make payments at the Inland Revenue Department's office or online. The tax calendar in Saint Vincent and the Grenadines runs from January to December, with tax returns and payments due by the end of March of the following year for both corporate and personal taxes. The VAT returns and payments are due by the 15th of the month following the end of the tax period.

It's important to note that Saint Vincent and the Grenadines has signed agreements with several countries for the avoidance of double taxation, which can help taxpayers avoid being taxed twice on the same income.