How early can you apply for a Covid visa extension in Thailand?

You can typically apply for a Covid visa extension 30 to 45 days before your current visa expires, but the exact timing can vary by immigration office. Some offices may allow applications as early as one week before expiration. For your specific case, where your visa expires on January 6, it is generally advised to apply a few days before, such as January 3. Keep in mind that your extension will usually take effect from the last stamp, not the date of application.