If a more serious error has crept into your ticket, you should contact the airline's call center in advance to clarify further actions.
British Airways
According to the official website of the airline, to correct most errors in the ticket, simply contact the British Airways call center (+38 044 585 50 50, Mon-Fri from 09:30 to 13:00 and from 14:00 to 17:00 or +38 0800 609327, Mon-Fri 09:00–18:00). There are no charges for corrections, but be prepared to send a scan of a document confirming your correct details. For more detailed information, call the phone number listed above.
Moreover, the airline allows you to cancel the reservation and receive a refund within 24 hours of payment, provided you made the purchase directly on the British Airways website.
Air France
Air France allows up to three minor errors in the passenger's name/surname in the ticket that do not change or significantly distort the meaning of the name.
If you purchased a ticket directly from the carrier and found an error in it, contact the call center or the company's representative at the airport for consultation. For ticket refund inquiries, call +38 089 323 98 44 — for calls within Ukraine and +33 (0) 1 70 48 5320 — for calls from abroad (Mon-Fri: 8:00-20:00, Sat-Sun: 9:00-17:30). Air France call center operators serve passengers in Ukrainian, Russian, and English.
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EasyJet
The airline is lenient about the presence of errors/typos in the name and surname on the ticket, if they (errors) do not significantly change the name and if there are no more than three of them. In this case, you can correct them online for free on the company's website or by contacting the call center.
However, if there is a more serious error in the plane ticket, you will have to pay to correct it. If you make changes more than 60 days before the flight - £20 (online)/£25 (via call center); if less than 60 days - £47 (online)/£52 (via call center).
Aeroflot
The company allows up to three minor errors in the spelling of the passenger's name/surname. If the error does not lead to another interpretation of the passenger's name, you do not need to correct the ticket, except for flights to the USA, China, India, UAE, UK, and EU countries. In this case, you need to inform the airline's staff at check-in to make the correction.
Unfortunately, the carrier's official website does not specify any specific sanctions for the presence/correction of gross errors in the ticket. To change passport details, you can use a special form.
Turkish Airlines
It's no wonder Turkish Airlines is considered one of the best airlines in the world - they are quite lenient about errors. There are no fines for them, and if there are no more than three errors and they do not change the pronunciation of the name/surname, there is no need to worry. The same goes for changing the order of the name and surname on the ticket.