Transit Visa

A visa required only because you're passing through a country's airport, not actually visiting — usually if you're leaving the international transit zone.

A Transit Visa is required when you pass through a country en route to your real destination — but only if you leave the international zone or need to collect/recheck baggage outside the airside area.

**Airside transit** — you stay in the international zone. Usually no visa needed.
**Landside transit** — you exit immigration, even to switch terminals or stay overnight. Almost always needs a visa.

**USA:** even airside transit requires a B1/B2 or C transit visa. A 1-hour LAX layover en route to Mexico City — you need a US visa.
**UK:** Direct Airside Transit Visa (DATV) needed for airside transit in most cases for Indian passport holders. There's a separate Visitor in Transit visa for landside.
**Canada:** transit visa (free, online) for layovers, even airside.
**Schengen Area:** Airport Transit Visa (ATV) required when transiting Paris CDG, Frankfurt FRA, Amsterdam AMS *en route to a third country*. Free, but you must apply.
**Australia:** transit visa (free) if you're not from a visa-waiver country.

The trap: if your bags are checked through to the final destination, you don't collect them — but if they're not (e.g., separate tickets), you must collect, exit immigration, recheck. That second step requires a landside visa.

The fix: always book a single PNR through to the final destination. The airline absorbs the transit visa rules into the routing.