In order to submit a visa application you must first make an appointment to visit the Swedish embassy. The appointment is booked trough a call centre. Please note that the Embassy is located on the 20th floor at One Pacific Place in Bangkok.
There are several private companies in the same building offering their services to visa applicants, but the Embassy has no link to these companies and the applicants are free to chose if they want to use the services of a company or deal directly with the Embassy. The applications must however always be submitted personally by the applicant. The application will be treated in the same manner regardless if the applicant has used a company or not.