Can WhatsApp messages be used as evidence in a UAE civil case?

Yes — UAE civil courts accept electronic communications as evidence, and WhatsApp messages and voice notes are relied on in money disputes regularly. The modern evidence framework gives electronic records evidentiary weight, so the absence of a signed paper does not doom your claim, especially where the chat shows the amount, the acknowledgment of the debt and the missed repayment promises in the other party's own words. What the court will care about is authenticity: that the account genuinely belongs to him and the messages are complete and unaltered. So preserve carefully. Keep the original chat on your phone and do not delete or edit anything; export the full conversation with media rather than relying on screenshots alone; keep the phone itself, because a court-appointed expert can verify messages directly from the device if authenticity is challenged. Bank transfer records showing the money leaving your account corroborate the chat and matter almost as much. For filing, the material will need legal translation into Arabic. Before you commit to litigation, have a UAE litigation lawyer look at the chat and the transfers together — they can tell you quickly whether what you hold is enough to file on.