When I signed up with the new Admob from the old one, my currency was set to Euros. That was late 2013.
Due to a variety of reasons I wanted to change my payment and reporting currency. The reporting currency could be changed but the payment currency would stay in Euros...
After researching I realized I had to open a new account and close the old one in order to change the currency, bear in mind that closing the account requires one to send an email to admob team.
I went about the procedure, opened a new account and set to dollars, I opened a new account with a different email address, linked all my apps again and got new Ad Unit IDs which I updated the apps with, soon revenues started streaming in, in my preffered dollars.
The apps on the old account were still making decent revenues as people don't update that fast so didn't want to miss out, but I knew it's against policy to have 2 or more admob accounts, I contacted admob team by email and told them of my plan to put a hold on my old account's payments so that the revenues still collected on the old account would be added on to those on hold as they wouldn't surpass the threshold and once that final payment is done, I'll have the account deleted and will request to have the new account associated with my original email address of the older account..
Their answer... They said it's OK but I shouldn't pass 2 months with both accounts.
After a month, the old account's revenues really slowed and as predicted couldn't surpass the 70 Euro Threshold, so the fact that I'd put the previous payment on hold enabled me to collect the 50 euros (Along with the previous month's revenue) I otherwise wouldn't have collected if I'd gone on to delete the account.
The account will soon be deleted, and I can request to have my old and preffered email address associated with the new account.
Hope this helps someone until better systems are implemented.