You cannot Authorize more than 5 Computers

Go into iTunes on your computer. View your account details. There will be a way to deauthorize all five computers. Then you can authorize, one by one, the computers you wish to use

This five computer restriction has been in effect for many years.

Five computers is the limit, I believe.

sberman's instructions are correct, so what is preventing you from deautorizing?

Learn how to authorize or deauthorize your computer with your Apple ID.

http://support.apple.com/kb/HT1420

You need to log into iTunes on the computer you want to deauthorise. Otherwise, you may need to contact iTunes Store support to see if they can help.

Again, go to iTunes on your computer. One way to view your account is to click on "iTunes Store" on the left, and then "Account" on the right. (There are other ways ... use the Store menu). Find a "Deauthorize computers" line there and do it.

The problem is that you can only authorise five devices. So I have an iPad that counts, an iPhone which counts, an iMac mini which counts, a Mac at work and then my girlfriend Mac. So that's five now what!? I'd quite like an ipad mini too. I might buy a nexus seven instead. But then what's the point in that as I'd still have to buy another copy of everything.! Nothing constructive here I just like to have a whinge

Stop whinning, you are wrong. it's 5 computer and 10 devices.

I wish I was wrong because then I would be able to buy a ipad mini and that would be wonderful. But I am not wrong. If I am wrong then why does it list my iPad and my iPhone in the list of authorised devices. And I say the word devices because that is what apple calls them. Devices. Not computers!

JP5000 wrote:

.... And I say the word devices because that is what apple calls them. Devices. Not computers!

Don't try to be too smart.

From this official Apple document

http://www.apple.com/legal/itunes/us/terms.html#SALE

I quote to make it simplier for you

Association of Associated Devices is subject to the following terms:

ℹ You may auto-download iTunes Auto-Delivery Content or download previously-purchased iTunes Eligible Content from an Account on up to 10 Associated Devices, provided no more than 5 are iTunes-authorized computers.

Got it now?

Thank you for being so full of knowledge and wisdom. So there are potentially 10 devices then. But only 5 computers (enough for anyone;) and that leaves you with room for 5 other devices. Or any combination there of, so long there's no more than 5 computers authorised to buy and download content. And seemingly you can borrow someone account and download their stuff but you'd have to wait 90days before switching back to your account. Is that correct? Will those apps still work? If so will you be able to update them. Will the songs still play? So I've de authorised all devices now. Lets see what it lets me do now. Is an Audible account different from a fullly authorised devise? Thinking out loud here. If I down load music on my work computer, then de authorise it but leaving the audible account still authorised. Will that work without taking up one of the slots? It appears that way. I'm sure you'll correct me if I'm wrong.

Well you have the same document as I have. Read it.

The OP has got the answer s/he was looking for. The thread for me is closed.

BTW, now you can buy your iPad mini and IPad 4th generation as well.

The only reason you can not de authorize, it is allowed once a year. In that case you can try to contact itunes store and see if they can help at Expresslane.apple.com. Make sure to pick itunes and itunes store. E-mail them

and see what they say.

Depending on what you're trying to do with more than 5 computers, there's work arounds. Download iPhone configuration utility. There's a limit to what you can do but not knowing why you need more than 5 computers, I can't tell you what to do :/