Yellow Fever should be planned before travel, not only at the airport. Airlines may check EASE, TSA, visa evidence and passport validity before boarding.
Cape Verde yellow fever checks can include accommodation, return tickets, funds, transit documents and purpose evidence even for travelers who do not need a tourist visa.
The safest approach is to carry both printed and digital evidence for yellow fever because final admission is decided at immigration.
Practical planning note
For cape verde yellow fever, the strongest file is the one that tells the same story across passport data, flight dates, accommodation, payment proof and the declared purpose of travel. This wording is tailored for the Cape Verde Yellow Fever page for entry requirements/yellow fever.
