“Valid Until” refers to a travel document’s date of expiry. For a passport, ICAO identifies the corresponding data-page field as “16 Date of expiry / Date d’expiration.”
How to check it
The reader should locate the date-of-expiry field on the passport’s data page and match “Valid Until” with the date recorded there. Other dates may appear on a travel document, but the ICAO reference specifically identifies the passport’s date-of-expiry field.
What the reader must still confirm
The expiry date does not by itself establish whether a separate visa, entry permission, or transit authorization is required. The holder must still confirm any applicable entry and document-condition rules for the intended journey.