I found a cheap, short-notice ticket which takes me from the Schengen area to India with a self-transfer at Doha (Qatar).

The booking process throws warnings such as (not verbatim) "You will have to collect your baggage and check it in yourself - As this involves passing immigration, you may need a transit visa".

  If it makes a difference, I will not have any checked-in luggage - Only cabin luggage.

My question is - In general, do I need a transit visa for B if I have two separate tickets A->B and B->C? If not, is there a globally applicable (subject to certain exceptions) rule to determine when I would need one?

  Is the first-carrier (A->B)likely to deny me boarding without a (transit) visa for B?

Extra-information: I fly Amsterdam-Istanbul-Doha on Pegasus, and Doha-Calicut on Indigo  (an Indian carrier) I hold a Belgian passport, and an Indian OCI card (which serves as a life-long, multiple entry visa), but nothing for Qatar.

I found a cheap, short-notice ticket that takes me from the Schengen area to India with a self-transfer at Doha (Qatar).

The booking process throws warnings such as (not verbatim) "You will have to collect your baggage and check it in yourself - As this involves passing immigration, you may need a transit visa". If it makes a difference, I will not have any checked-in luggage - only cabin luggage.

My question is: In general, do I need a transit visa for B if I have two separate tickets A->B and B->C? If not, is there a globally applicable (subject to certain exceptions) rule to determine when I would need one? Is the first-carrier (A->B) likely to deny me boarding without a (transit) visa for B?

Additional information: I fly Amsterdam-Istanbul-Doha on Pegasus, and Doha-Calicut on Indigo (an Indian carrier). I hold a Belgian passport, and an Indian OCI card (which serves as a life-long, multiple entry visa), but nothing for Qatar.