Can two authors in partnership write under one pseudonym?

Today, I had an interesting book question about using a pseudonym as an author, where there are two individuals involved. Let's take a hypothetical name A. B. Cartwryte, and that this is the pseudonym for two of you, Allyson and Bernard Cartwryte.

Let's say it right from the start, many authors do write under pseudonyms.

From a publishing perspective, there is no problem with the author being A. B. Cartwryte.

Where your pseudonym will become an issue for you personally, is with:

1. Your copyright – A. B. Cartwryte will have it. You need to make clear somewhere that this is either 
1. both you as Allyson Cartwryte and Bernard Cartwryte jointly 
2. OR that you, Allyson Cartwryte are writing as A. B. Cartwryte and are the sole copyright holder. 
3. The decision is yours.
2. Correspondence – for simplicity’s sake and to avoid confusion of the recipient, you need to use your pseudonym with readers writing to you. Make sure therefore that you have email addresses for you as Allyson Cartwryte, and possibly also Bernard Cartwryte, if you both take responsibility for the book. 
3. Payment – people will automatically send payments to A. B. Cartwryte or want receipts/invoices in that name. you might want to let your bank know in advance that either you, Allyson or you and Bernard may receive payments in that name, so payment’s don’t bounce. If your place of residence allows, you might set up a separate account for the book. This also makes it easier for later tax purposes.

There are two great articles on the issues arising from using pseudonyms here:
http://writersrelief.com/blog/2008/06/pen-names-what-you-need-to-know-about-using-a-pseudonym/
http://writersrelief.com/blog/2009/02/pen-names-ii/

Please don’t just take my word for it but check out the implications for yourself and your situation, if you are thinking of writing under a pseudonym.