Is 'flight credit' the same as a refund?

No. A refund goes back to your bank account. Flight credit forces you to spend money with that specific airline again within a set timeframe (usually 12 months).

Can I upgrade to a flexible fare after I book a cheap ticket?

Rarely. Most airlines do not allow you to retroactively add flexibility to a 'Basic' ticket. If you aren't sure, pay for the flexibility upfront.

Booking Flexible Flights When Your Plans Are Uncertain

To secure flexibility, book directly with the airline using 'Economy Flex' or 'Premium' fare classes rather than third-party sites. This ensures you can change dates or cancel for flight credit without paying exorbitant change fees or dealing with non-responsive customer service.

Use a search engine to identify, not book. Use Google Flights to track routes and price history. Do not book through the links provided there; use them only to identify which airlines fly your route and what their fare rules look like.
Filter for direct airline bookings. Go to the airline's official website. Never use an OTA (Online Travel Agency) like Expedia or Kiwi if you need flexibility. OTAs often block airlines from managing your booking, leaving you stranded if you need to change dates.
Select the 'Flex' or 'Fully Refundable' fare. Look for fare buckets labeled 'Flex,' 'Business Flex,' or 'Refundable.' These typically cost 20–40% more than the 'Basic Economy' fare but allow changes for zero fee or offer full cash refunds.
Confirm the cancellation policy before payment. Click the 'Fare Rules' link. Ensure the policy explicitly states that 'cancellations are permitted for a full refund to the original form of payment' rather than just 'e-credit.'
Set a calendar alert for the flight date. If you are booking a flexible flight, you are likely waiting for a specific event to be confirmed. Set a reminder 48 hours before the flight to either confirm your travel or cancel/rebook your ticket.

Is 'flight credit' the same as a refund?: No. A refund goes back to your bank account. Flight credit forces you to spend money with that specific airline again within a set timeframe (usually 12 months).
Can I upgrade to a flexible fare after I book a cheap ticket?: Rarely. Most airlines do not allow you to retroactively add flexibility to a 'Basic' ticket. If you aren't sure, pay for the flexibility upfront.