Shoeshone

Hi, I am currently in Oz on holiday, I have been offered a Plumbing job in Vic on a 457 sponsored job. I have been informed by a Visa company that I need to have a letter from the Australian Licencing to acknowledge my plumbing qualifications. Can any one tell me who I need to contact ? as the employer has said that they will give me 12 months to have my qualifications upgraded to Australian ones.