First assess whether the change affects the substance of the trip. Switching hotels in the same city differs from moving the main destination to another country. During a pending application, notify the relevant authority of significant changes and provide updated documents as instructed. After issuance, seek guidance from the issuing authority if the purpose, main destination or entry arrangements change materially. Not every change automatically invalidates a visa, but outdated reservations should not be presented as current. Keep the revised itinerary and evidence of the genuine reason for the change, and separately check the limits shown on the visa sticker.