Our FFM are with Delta would be extremely difficult to pull that off. First, flights are usually cheaper roundtrip, then if you are only traveling for a few weeks then you run into flights that are more expensive if you book less than 2 weeks out.

Flights vary a great deal depending where you live and the time you are flying. I find I can get the best "deal" if I am flexible about date, time and city. Set your goal as the cheapest flight from where you live(or your closest large city) to almost any major European City. Then go on to this site http://www.whichbudget.com/ and find a flight from your roundtrip place to your destination.

Check flight and options frequently until you get a sense of prices and then book.

That's not going to work for the two reasons mentioned above: round trip will be significantly cheaper than two one ways, plus booking within a few weeks of when you want to fly will also be significantly more expensive. PLUS - UK immigration is going to want to see proof that you plan to leave - the return ticket - or they may not let you into the country at all. Really doubt that plan would work at all.

The suggestion to find the cheapest city to fly to then fly easyjet or some other budget airline to where you really want to go (in this case the UK) CAN work - but often it just costs almost as much plus eats up a lot of time. I have certainly done that, especially if my actual destination is someplace extremely expensive to fly to - such as Croatia, or Turkey or Greece. But the UK is usually about as cheap as you are going to find. Also, so as to not risk missing the second (budget) flight, you should really leave at least a day between when you land and the next flight leaves (if the transatlantic flight is late and you miss the other one you are stuck, you'd have to buy a last minute expensive ticket). (I am assuming you are coming from the US, if you are starting in the mid or far east then it might make more sense.) Works OK if you are on a trip of a month or so and don't mind an extra night somewhere, but not worth it for shorter trips.

Try kayak. Also look specifically at IcelandAir and Aer Lingus.

could we then use the miles that accumulate on the trip over to offset the flight home, knowing full well that we'll have to book our flight home AFTER we arrive.>>

honestly, i think that would look very dodgy to any alert immigration officer. ok, you might get a dozy one, but do you want to take that risk? also, you take the risk that you can't find a flight back at a price you like, or at any price.

sad to say, I think that booking both ways is the only sensible thing to do. you might get a multi-city into Glasgow and out of London at a good price, or you might not. if not, i would suggest going straight from London [assuming that's where you arrive] to Glasgow, and working your way back. that way you end up in the right place for your journey home without the hassle of worrying about making connections. however, taking account of what isabel says, you might want to give yourselves a couple of days in London first so as not to run the risk of a late flight mucking up your travel plans.

alternatively, plan to get the train to Glasgow - it might take most of your arrival day, but given jetlag and general tiredness, what else are you going to do?

You are unlikely to accumulate enough points on the first flight to have any significant effect on a subsequent purchase. Read the airline website fine print carefully; frequent-flyer plans are complicated, especially for redemptions, and often impossible at the last minute as the number of eligible seats can be limited. To put it simply, points are not the same as cash in the bank.

No, there is absolutely no way this plan would work, for all the reasons given above, and then some.

I think your concern should be in other places as previous posters indicated. Getting miles credited is a lesser of the problem. I have have no problem FF info linked to my itinerary using booking sites. Even if does not happen, I can always tell which FF to credit at the check-in time.

I think an attempt to use the scheme described would loyally backfire on you. Beside the high starting price for one way fares as well as last minutes fares, FF redeeming is difficult with all kinds of fine print restrictions. Additionally, they can be delays between the time you take a trip to crediting your account. Further stacking the odds against you is that you are trying to do this in June, a high season.

The short answer - nope. Won't happen.

If out-of-pocket cost is your main consideration, just book the cheapest flights you can find, no matter the airline/FF program. In the long run, open jaw will likely be cheaper than R-T when you factor in the extra cost/hassle of back tracking to your arrival airport.

British Air has a sale on now. See if the fares work for you. Easy to do a multi-city trip right on BA site. What is the advantage of using a 3 rd party booking site??

The system does;t work this way.

First- RT tickets are typically way cheaper than two one-way tickets

Second - tickets bought at the last minute are usually much more expensive

Third: It takes a certain amount of time - not just days - for mileage to accrue to your account -

4) and the very few miles you would get for joining and 1 flight wouldn't earn you anything (it usually takes miles from a fair number of flights to earn you anything). (I used to fly on points all the time and it took most of the year making at least 1 RT per week to get a decent award.)

Sorry - this is a fantasy - you should just search for the best flight costs you can.

I did some looking about and it seems that you may save some by flying into London first. From there Edinburgh is a bit less than Glasgow. You could save a few additional dollars flying into Manchester instead of London if you are interested in exploring that part of the UK and then on to either Glasgow or Edinburgh.

This all assumes leaving from NYC in mid June, mid week.

Our Capital One credit card -- the one with no fees in Europe -- has allowed us to book travel, then use the points we earned on the same trip to offset part of the cost when the credit card bill came.

I don't know the details because I don't handle the family books, but we have done it twice. You call the rewards center when you get the bill, and they transfer points to offset the cost. Or something like that!

You wouldn't earn enough miles going over to pay for the return trip, and even if you already had some miles and just added to them, paying for one-way outbound and redeeming miles (actually, BA "Avios") coming back would force you into a very expensive fare class on the paid one-way trip. You wouldn't save anything at all, and if fact would pay way more all in.

Not to mention, "award" seats (i.e. mileage redemption) can be very hard to obtain during peak seasons.

The itinerary you're planning - to Glasgow and from London, is called an "open jaw" itinerary and as long as you book it on one ticket, the total cost will be very close to the round trip fare either to Glasgow or London. This is done all the time and can be accomplished by using the "multi-city" (or similar name) function in any online booking site, or with an airline itself.

You'll accrue miles if you book through most online sources, with the exception being "consolidators" who sell deeply discounted tickets in fare classes that don't earn miles/Avios. Consolidator tickets also carry very heavy restrictions regarding changes, refunds, etc., that also make them less than desirable for many (most) people.

Now the good news.

Glasgow is a great place to arrive in the UK. It is a brief flight from the US East Coast (~5 hours), has very short immigration lines, and has good bus links to the city center and Edinburgh. Cabs are not expensive.

I have NEVER had ANY immigration officer in the UK ask me to show a return ticket!

"I have NEVER had ANY immigration officer in the UK ask me to show a return ticket!"

But they can and do ask LOTS of travelers for that very thing.