Developers usually check Serial Box releases and public boards like MacSerialJunkie to find the new numbers published for their apps so they can ban them in their next updates. Then, if you try to use that number, a window will pop up with a message like this one (or similar):

"You Are Using A Stolen Serial Number, Shame On You!"

Some developers just ban the fake numbers in a way that's very easy to hack. They include a list of banned numbers inside the application code. But, because they do not encrypt these banned numbers, you can simply change a single letter or number in the banned registration and then register the app using the banned number!

To make this type of change you can use the app of your choice. Just check the "ASCII" matching button if you use HexEdit or uncheck the "Hex" checkbox if you use Resorcerer. Then simply search for find the banned username, e-mail or number and replace it with something else the same length.

We'll check this using HexEdit only, but it is the same if you use Resorcerer (just uncheck the "Hex" checkbox).

Name: PHREKBBS 
Code: 5123-9826-3615-9834

The developer banned that registration, but he didn't encrypt the banned registration so it's very easy to find:

1. Launch HexEdit and go to the menu Find/Find... The search window will appear. Check the "Matching ASCII" button and write PHREKBBS in the "Find" box. Then click the "Find Next" button. You'll see this:



2. You can replace the PHREKBBS name changing any character of the name, or you can simply write another name with the same number of characters. For example you can write KCN-CREW in the "Replace with" box and then click the "Replace" button. You'll see this:




Now the banned name is KCN-CREW while PHREKBBS is free again.

3. Close the search window, save changes and quit HexEdit. Now you can launch the modified app and register it using again:

Name: PHREKBBS 
Code: 5123-9826-3615-9834