What documents do I need for a visa extension in Thailand if I entered by Visa Exemption?

To extend a visa in Thailand, especially for those entering under the Visa Exemption with a UK passport, the required documents generally include a passport, a passport photo, a completed application form, and a fee of 1900 THB. However, requirements may vary slightly between different immigration offices. It's advisable to check with the specific office or consult with locals for the most accurate details.