What to do
Always include the booking reference, passenger names, flight numbers and dates in the first lines. Keep the tone calm and direct. Say what you want in one or two clear sentences, then ask for the available options and the total cost if any. Send from the same email address that was used for the booking when possible. If you get no answer after a few days, send a short follow-up with the same subject line.

Three options
First option is a simple date change request. Use this when you only need a new departure day on the same route. It is the most common and usually the easiest for the airline to process.

Second option is a cancellation and refund request. Use this when the flight is no longer needed and you want money back or at least the returnable taxes. Be clear whether you prefer cash or are open to a credit.

Third option is a route or stopover change. Use this when the destination or connection needs to be different. These requests take a bit more checking on the airline side so keep the message clean and specific.

Cost
Writing the email itself costs nothing. The change or cancellation fees depend on the original fare and the airline rules. Always ask for the full amount before you confirm anything so you know the exact number.

Ready templates

Template for date change
Subject: Date change request – booking [code]

Hello,
I would like to change the date of my flight under booking reference [code].
Original flight: [number] on [date] from [city] to [city].
Preferred new date: [new date], same route if possible.
Please let me know the available options and the total cost.
Thank you.

Template for cancellation and refund
Subject: Cancellation and refund request – booking [code]

Hello,
I need to cancel booking [code] and request a refund.
Flight: [number] on [date] from [city] to [city].
Please confirm what amount can be returned to the original payment method and the expected processing time.
Best regards.

Template for route or stopover change
Subject: Route change request – booking [code]

Hello,
I would like to change the route of booking [code].
Current itinerary: [cities and dates].
Preferred new route or stopover: [details].
Could you check the options and reply with the possible flights and the exact extra cost?
Thank you.

Template for short follow-up
Subject: Follow-up – booking [code]

Hello,
I sent a request regarding booking [code] on [date] and have not received a clear reply yet.
Could you please update me on the status?
I am happy to provide any additional details needed.
Thank you.

Summary
Clear short emails with the booking reference right at the top get answered more often than long explanations. Choose the template that matches your situation, fill in the blanks, and keep the tone polite. Ask for options and the full cost before confirming. Save every reply. Most people who write this way receive a usable answer within a few days and can move forward without endless waiting.