If you needs to work with more than 10 financial dimensions – in addition to the main account – you will quickly notice that you are not able to add more than 10 financial dimensions in the account structure configuration window (see the following screenshot).

This does, however, not mean that you are not able to work with more than 10 financial dimensions in Dynamics AX 2012. That is because another 11 financial dimensions can be added via the advanced rule structure window allowing you to make use of 21 financial dimensions in total. Example:

All of those 21 financial dimensions can be analyzed via the Dynamics AX Management Reporter. Example:

If you try to do a similar analysis via the trial balance list page in Dynamics AX you will notice that this cannot be done without making a system modification because the required financial dimension set only accepts a max. number of 11 financial dimensions (main account + max. 10 financial dimensions).

A possible workaround is setting up several financial dimension sets that include max. 11 financial dimensions.