If an airline on which you have a ticket cancels or delays your flight significantly, you have an absolute right to a prompt full refund. The refund must include any ancillary fees you purchased such as a checked bag or seat assignment. That's the gist of a final rule published last week by the Department of Transportation (DoT), and it establishes that right firmly and with no exceptions.

The rule applies to both foreign and domestic airlines, for flights within, to, or from the United States. The final rule doesn't establish any major new consumer protection but it does define and codify previously established rights. Prompt Defined.

Prior legislation requires prompt action, and the final rule defines prompt as "refunds made within seven business days after the earliest date the refund was requested for credit card purchases, and within 20 calendar days after the earliest date the refund was requested for cash, check, debit card, or other forms of purchase," Significant Defined. According to DoT rule, a refund is required when a delay is significant or a cancellation results in a significant delay in a consumer's reaching his or her final destination. Significant is now defined as three hours for a domestic flight and six hours for an international flight.

Responsibility Defined. The party responsible for making the refund is the party through which a consumer purchases a ticket. That can mean an airline, for a direct purchase, or a travel agency, online or bricks-and-morta.