The 28-day rule
The FTA states that VAT returns and the related payments are due within 28 days from the end of the tax period. For a quarter ending 31 March, that means 28 April. For a quarter ending 30 June, 28 July. Payment must reach the FTA by the same date, so start bank transfers several working days earlier.
Your tax period and its stagger are shown on your registration certificate and in EmaraTax. Most small businesses file quarterly, but quarters do not always follow the calendar: one company's quarter may end in March, another's in April or May.