Hi,
Out of interest are you thinking of making the move from Dynamics GP to Business Central. Its just the account format you use is very similar to how the chart of accounts is setup in Dynamics GP.
If so as Kim and others have mentioned, when moving to BC you'd use the "Main Segment" (Dynamics GP term) as the "No." in the Chart of Accounts in BC, and create the other segments as dimensions. In my opinion this gives greater flexibility than GP as you aren't stuck to a rigid format. You also don't have to create lots of codes if you introduce a new dimension (again something Kim mentioned)
Therefore using the Dynamics GP Fabrikam company as an example, and based on the account format below, you'd use "Account" as the "No." in the Chart of accounts and create "Division" and "Department" as dimensions. Then you could create additional dimensions as and when you needed.

I've also blogged about the differences between the chart of accounts setup in Dynamics GP and Business Central in this post thedynamicsexplorer.com/.../
Even if you don't use GP I hope this helps
Thanks
Gavin