What documents are needed to extend a 60-day entry visa by 30 days in Thailand?

To apply for a 30-day extension of your 60-day entry visa, you will need to provide certain documents, which may vary slightly depending on the local immigration office. Generally, applicants should prepare the following: a valid passport, a completed application form, a recent passport-sized photo, proof of funds, and any additional documents as required by the specific immigration office.