Typically, a business visit invitation letter can be issued by a company already registered in the UAE or by a local business sponsor. Work visas and family visa invitation letters are usually applied for by the registered company acting as the employer. The application process generally involves preparing relevant materials, such as company registration documents, applicant passport information, employment contract (for work visas), proof of family relationship (for family visas), etc. These documents are then submitted to the local immigration department or relevant authorities. Once approved, the invitation letter can be obtained. (Adam)

