What airlines do not penalise you for buying one-way flights?

What airlines do not penalise you for buying one-way flights? Need to fly to TVL but returning from IST and it s a hassle!

The Low Cost Carriers...

I would have thought it would have bene most airlines these days do not penalise you for buying a one-way ticket. Most of the time the flights are priced on a one-way basis, a return booking is simply a matter of choosing 2 x one-way fares, one to get from A to B and the other from B to A.

I should point out that while this is true (especially for LCCs), there are airlines (e.g. QFi) that only offer one-way fares in higher brackets, e.g. Flexi Saver and so on; the deeply discounted sale fares must be booked return.

Domestic yes, international no.

I suggest searching for open jaw tickets, starting from airlines that operate to both IST and TVL (I assume you meant TLV?). Depending on where your origin is, for example Korean Air can connect you to both IST and TLV via Seoul if you depart from Sydney. 

Thanks - yes it was Tel Aviv!

Flying into TLV and out of IST should be able to be booked as a multi-stop ticket without penalty. Sometimes in these situtations its good to see what a travel agent can do for you - I'd just email a couple and see what options they can provide.

What route and what class are you trying to fly? Do you have transport between TLV and IST booked already?

TLV to LGW on Easyjet, LGW to IST on Turkish. I'm aiming to buy miles to fly business award on OneWorld (eg AAdvantage), StarAlliance or SkyTeam. Trip not until Feb-Mar next year but I started planning after reading here about the AAdvantage miles sale (for which I won't qualify as my account won't be 14 days old by the time the sale ends tomorrow...).

I'd suggest flying on the award ticket to the middle east if you do not have sufficient miles for a return ticket. You can then take advantage of cheap business class fares from Cairo, Muscat, Colombo, India and many similar countries in the region (no, not UAE or Qatar).