Yes, you can cancel United Airlines flights and receive a refund, but the eligibility and amount depend on the ticket type and timing.

24-Hour Cancellation Policy: United allows free cancellations within 24 hours of booking if the flight is at least seven days away. This applies to all fare types, including Basic Economy, provided the booking was made directly with United.

Refundable Tickets: If you purchased a refundable ticket, you can cancel at any time before departure for a full refund to your original payment method.

Non-Refundable Tickets: These tickets are generally non-refundable. However, you may receive a travel credit for future use, minus any applicable cancellation fees.

Cancellation Fees: For non-refundable tickets, cancellation fees typically apply. The fee for domestic flights starts at $200, while international flights can have fees up to $400, depending on the route and fare class.

No-Show Policy: Failing to cancel a reservation before departure results in a "no-show," leading to the forfeiture of the entire ticket fare without any refund.

Special Circumstances: In cases of death in the family, medical emergencies, or government orders, United may waive cancellation fees upon verification of relevant documentation.

Cancellation by the Airline: If United cancels a flight, passengers are entitled to a full refund or can choose to rebook on another flight at no additional cost.

Refund Processing: Refunds are processed to the original form of payment. For credit card purchases, refunds typically take 7–10 business days, while cash payments may take 20–25 business days.

Electronic Vouchers: In certain cases, United may offer an electronic voucher worth 115% of the ticket value (excluding taxes) for future travel. These vouchers are valid for 12 months from the date of issuance.

It's important to review the specific terms and conditions associated with your fare type and booking method to understand the applicable cancellation policies and fees.