Hi all,
I was wondering if it would be smart to sign up for a BA account I already have an American account. The only thing I could see this being useful for is the fact that Avios are a better deal generally then American Miles. A problem I could see is once I get status that status can't be used if I have status on AA and I put my BA # in correct me if I am wrong on that.

What is your objective and how many miles are you expecting to earn? Crediting to two different programs will make it more difficult to achieve elite status, if that is your objective.

Each of BA and AA have their own benefits, and there can be wisdom in having both in some circumstances. But if you're not going to be earning many miles, then having some "orphaned" in a different program isn't good.

Yes, it depends on what you plan to use the BA account for. For example, I credit and earn status on AA, but also have a BA account mostly for award flights using Avios. And I still get all benefits of OW status earned through AA when booking awards using Avios on OW flights.

Blake Baldwin Welcome to FT

How much flying do you do?
Do you fly BA or IB?
Do you have many AA ff miles/AA status?
What do you use the AA (& DL) ff miles for

Each ffp has good & bad aspects

BA status reqires 4 qualifying BA/IB operated and/or marketed flights. Full details on BA web site and FT BA forum (sticky threads)

One advantage of BA ffp is that OW Sapphire/Emerald status will get you lounge access on USA domestic/regional flights where as the same OW AA status will not.

BA freq flyers do not get AA upgrades as much. The cross airline AA/BA/IB upgrade system has onerous t&c's and requires an expensive base fare booking class.

AA awards are by broad zones. BA awards generally by distance. BA awards are known for award cash carrier surcharges. An AA award on BA also has the cash surcharges. BA frequent flyers only have access to AA saver awards (not AAnytime)

Airlines ffp are being more restrictive on cherry picking status benefits/swapping ff numbers. Some posts in the AA forum on that topic (JonNYC)

Look at post 3 here. Oneworld:- Deciding on a Oneworld Frequent Flyer Program? Help is here

Be mindful of expiry Miles/Points that Do and Don't Expire. Click to open the wiki.

The grass in not always greener on the other side

I fly American and Delta about the same amount of time each year. I would really only use BA for Avios that is what my parents do cause they have a BA Chase Visa Card. I would like to use miles for booking award flights because I don't really fly International often and I am fine with Eco on Domestic flights.

Depending on the particular domestic award itineraries you fly, IB Avios can be better value than BA Avios -- especially if your award travel requires connecting flights. BA charges for each flight flown; IB charges based on the total round-trip flight distance. But IB Avios redemptions on AA are completely non-changeable/non-refundable.

How so? I frequently use BA to search award flights that I later book with AA miles. The prices in both Avios and cash that BA shows are generally higher than what AA charges.

Also, my understanding is that BA charges per flight, while AA charges region-to-region, for one to four flights (for international).

I'm based in Europe and have both an AA , a BA and an IB Avios account.
I credited everything to AA until last year because AA was a better program for both redemptions as well as status. It was much easier to earn status with AA until they changed the program and now look at dollars spent instead of miles flown.
I only used Avios to book short OW Award flights (the last one was a JAL flight from Japan to South-Korea).
The IB account is because Iberia often sells Avios on Groupon. The first few times it was a very good deal but recent offers were much less interesting.

Last year I haven't been loyal at all (only one OW flight with British). I'm not sure what I will do in the future.
All my flights are leisure and I'm price-conscious, I will only book Business when it's a good deal. Redeemable miles earned on AA are peanuts but BA is not that much better in that regard. I think it's slightly easier to earn status with BA if you fly business.

As I'm based in Europe I think I can now get slightly more value from BA's program.
I used AA miles for long haul business flights which offered great value.
As it is much harder to collect miles with cheap economy flights I think I might be better of now collecting Avios and spending them on short Economy award flights.

That's my 5 cents based on what I know about the 2 programs. I didn't do an in-depth study and I must say I'm still in doubt (it's much more fun to use award miles for comfy lie-flat business seats) so I still want to do some more homework before I decide.