When I joined my current employer (as a volunteer before being given a job), the previous staff who had left didn't utilise Sage's procedures properly; I also knew absolutely zero about Sage processing (one of the reasons I originally joined as a volunteer was to learn Sage, along with getting practical experience of the theoretical accounting I had studied).  As a result I had to work out what had been happening and what was needed to continue the processing, and so developed ex-Sage (excel) month end processing to create the journals to enter.  We are slowly converting the processes to Sage (when time allows).

Since our year end last July, we have still not yet closed our accounts (done a year end) as we wait until the auditors are happy to avoid any faffing around having to put any previous year adjusting journals in.  As we still need management accounts (6 months later), we continue to process our month ends with the required journals.  (I create the MA ex-Sage as Sage can't handle future months other than in a single figure which doesn't help us, plus it allows a lot more freedom regarding fixing the CoA with its split ranges.)

You should be able to do the normal data entry and month end processing for every month going forward before you close your accounts - just note that you will only get a single Future value until you process your year end¹.  If you want the TB as at the end of December (or any date) you can use the Transactional TB report as this allows you to create the TB up to a given date (and/or transaction - this allows you to recreate a TB from the past²).

Sage's Month End processing basically handles automagically all the jobs you would have to do manually (eg prepayments, depreciation), along with setting the lock date to the start of the next month.  The lock date is intended to prevent adjusting prior figures, but there are occasions when this is necessary (eg a late adjustment is needed) and Sage allows those with the necessary permissions to override the lock date and post transactions prior to it.

So even after you have run the December month end you will still be able to put journals in for that December whilst you continue to use Sage for your January, February, ... transactions (including doing their month ends).

¹The year end process basically clears down your P&L to the BS (reserves) by adding the journals necessary to move the values.  If you need to adjust anything in the P&L for that year subsequently, not only do you have to enter the P&L journals, you also need to enter the clear-down journals.  It is to avoid this faffing around that we wait until the auditors are happy with the accounts before we do the Sage year end procedure.

²assuming no included transactions have been edited

Hi Edward, 

Our Onion software is designed to do all routine reporting from the underlying transactions. That means it operates independent of Sage's year end processes and reports can be run for any financial year at any time.

The software "snapshots" your Sage transactions at time of running and saves them in a stand-alone Excel workbook incorporating a comprehensive suite of Balance Sheet, P&L, TB and Cash based reports and graphs. Given 1) and 2) in your original post: we would run our Onion software for the December internal management accounts at point 1), creating a pre-CT financial position file for the year; and, run Onion again at point 2), creating a post-CT financial position file for the year. 

We have a free 30 day trial for our Onion software. I'd be happy to demonstrate what the pre and post CT outputs would look like if you wanted to run it against your data.

Food for thought. HTH.

Kind regards,

Ian