How long
The general rule under the UAE tax procedures framework is that records must be kept for at least five years after the end of the tax period they relate to. That lines up with the FTA's general five-year window for audits and assessments, which the 2026 amendments to the Tax Procedures Law retained, with listed exceptions. Longer periods apply to certain records, notably those relating to real estate, so check the FTA rules if you own or deal in property.
In practice, keep VAT records for the current year plus at least five full years, and do not destroy anything relating to an open query, a refund claim or a voluntary disclosure.
Remember that the clock is tied to the tax period, not the date you received a document. A supplier bill dated 3 January for a quarter ending 31 March is kept for five years from 31 March, not from 3 January. When in doubt, keep it a little longer; storage is cheap and a missing document during an audit is not.