AirHint found the following cheapest return flights from London (LCY) to Sofia (SOF) in September 2025 (see full year).

Return flights

19 Sep - 23 Sep	SWISS
19 Sep - 22 Sep	SWISS
29 Sep - 13 Oct	SWISS
29 Sep - 01 Oct	SWISS
19 Sep - 10 Oct	SWISS
12 Sep - 16 Sep	SWISS
02 Sep - 03 Sep	SWISS
12 Sep - 18 Sep	SWISS
16 Sep - 18 Sep	SWISS
16 Sep - 23 Sep	SWISS
02 Sep - 15 Sep	ITA Airways
16 Sep - 22 Sep	ITA Airways
02 Sep - 04 Sep	SWISS
27 Sep - 01 Oct	ITA Airways
29 Sep - 21 Oct	SWISS
30 Sep - 03 Oct	ITA Airways
29 Sep - 02 Oct	SWISS
30 Sep - 07 Oct	Lufthansa
10 Sep - 13 Oct	Lufthansa
24 Sep - 08 Oct	Lufthansa

Also check the deals for one-way flights from London to Sofia in September.

The deals are updated regularly. The prices may go up as tickets are purchased by other travellers. Only the cheapest flights are offered. Select a price to book and secure these cheap prices.

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Cheapest return flights from London to Sofia in September from 205€

Return flights