Failure to provide all supporting documents can lead to the rejection of your visa application. The lack of documentation, such as employment letters, hotel reservations, proof of financial means, etc, make your visa application seem ingenuine and incomplete.

Schengen visa applications are most commonly rejected due to insufficient or inconsistent documentation. Frequent reasons include a lack of "Proof of Subsistence" (not showing enough funds in your bank statements to cover your stay), invalid travel insurance (it must cover at least €30,000 and be valid across the entire Schengen area), or an unclear "Purpose of Stay." Consulates also heavily scrutinize the "Intent to Return"; if you cannot prove strong ties to your home country through employment, family, or property, they may suspect you intend to overstay. Other factors include a previous history of visa violations, an invalid passport (less than 3 or 6 months validity remaining), or an "SIS Alert" (a flag in the Schengen Information System for prior legal or immigration issues). Providing a detailed, confirmed itinerary with flight and hotel bookings is essential to avoid a rejection.