I'm actually having the same problem but USA via UK haha.
So if you want to trade US stamps for UK please let me know by PM! I really need some

Yes,the poster below me has the correct advice.

usps.com only takes telephone orders if you're ordering from outside US, not through the website.

Check out the Collecting Help section of the forum, this question comes up alot

IRC's no longer exist in the UK. I have purchased US stamps from user bri0626 on the forum. Very reliable.
I have found that 3 x $1.10 stamps covers the postage from the US to the UK of a board backed envelope containing a 10x8 photograph. The other way I have used is to sent the letter of request with an addressed envelope and $3 in cash

Hope this helps

Thank you! I will try that

I want to send for an autograph to the US (I live in England), but I don't know how to get an international reply coupon. I don't think they're available in the UK any more.
Does anyone know of a way around this?

Thanks.x