If they require TM87 iso TM86 that says a lot, I think.
1.1 Form TM.86 for the foreigner, who has Tourist or Transit Visa and want to applies for a change of type of visa (from Tourist Visa or Transit Visa to Non-Immigrant Visa); or
1.2 Form TM.87 for the foreigner, who enters the kingdom of Thailand without visa, but is allowed to stay in the kingdom with a permit of stay for a period of 30 days, 90 days and want to applies for non-immigrant visa.