sfo to lhr and return (return changeable)

Does any airlines offer changeable return ticket between sfo-lhr-sfo ?

In case they charge, how much is it ? and who charge the least ?

I am planning to go to London, but don't know the exact return date.

Please help.

Joydeep Roy Chowdhury wrote:

Does any airlines offer changeable return ticket between sfo-lhr-sfo ?

In case they charge, how much is it ? and who charge the least ?

I am planning to go to London, but don't know the exact return date.

Please help.

All airlines that fly from SFO to LHR offer changeable return tickets.
The ticket price depends on a lot of variables. There is no generic
answer to this question.
You really need to spend time doing some research, or consult a travel
agent.

Joydeep Roy Chowdhury wrote:
Does any airlines offer changeable return ticket between sfo-lhr-sfo ?

Lots of them. Every airline offers changeable tickets. It's only when
you decide to get a reduced price ticket by accepting restrictions that
the tickets become unchangeable. Full fare tickets can always be
changed.

In case they charge, how much is it ? and who charge the least ?

If you want changeable then you don't get to ask "who charges the
least". Low price is what makes a ticket unchangeable.

Would you accept Gatwick instead of Heathrow if it was cheaper? If so
then you've got about a dozen airlines to choose from.