How to copy a company account in Ax

When you are using Dynamics Ax, you probably have more than one instance running besides your Live Production system.  Maybe you have some development environments, or test environments.  But even then it can be useful to have a copy of a company, within your Live Production environment.  You can use it for testing purposes or for starting up a new company, with similar settings as the current one.
Microsoft made it actually quite easy to duplicate a company account within Ax, it's almost by clicking a single button.

Step-by-step guide:

Go to Administration - Common forms - Company accounts.

Select the company account you want to use as template, your source to copy from.  Then click Duplicate.

Wait a sec, Ax is investigating the company account.

Next, enter a new company account id, followed by a company name.  (Ax will create this new company account for you, you don't have to manual create one.)

Click OK and you're off.  Depending on the size of your source company account, this can take some time (think of hours).  Not only your master data is duplicated (customers, items), but also all the transactions from the source company account (like inventory transactions, ledger transactions).

You might wanna perform this duplicating outside of office hours and using a batch server for this is also a good idea.

Also note:
The guide above works for Ax 2009, but it won't work in Ax 2012.  In Ax 2012, this function is no longer available, it got deprecated.  Reason, from the official MS documentation: The organization model represents a paradigm shift in Microsoft Dynamics Ax 2012.
In short: You must rely on import and export again in the future.