It's not compulsory to run the month end procedure, but it can be useful under some circumstances.

If you use things like the fixed assets module, for example, then that posts the monthly depreciation as part of the month end procedure.

If you feel it does need to be done, then it's Tools -> Period End -> Month End

And if last month's hasn't been done, then before doing this month you can run it for last month by changing the program date in Sage to the end of last month. Settings -> Change Program Date

If memory serves, though, you can only go back and perform month ends as long as no subsequent month ends have been run. For example: If January, February, and March have been done, then you can do April by changing the program date, and then May after changing it back. However, if January and March have been done, then you can do April and May, but you can't go back and do February.

A query on what Sage did in your trial, then.

If you had a recurring transaction or some monthly depreciation, when you do the May month-end, did it do the monthly stuff for both April and May at that point? Or did it only do the May stuff and when you went back and did April, it then did the April stuff?

I sincerely hope it's the former, otherwise you could miss out a month and all the depreciation, etc, figures would be wrong. However, it is was the former, what does Sage actually *do* when you run the April month-end procedure?

Okay, I've now tested it with an item in the fixed asset register - and I'm reverting to my original position:

"you can only go back and perform month ends as long as no subsequent month ends have been run. For example: If January, February, and March have been done, then you can do April by changing the program date, and then May after changing it back. However, if January and March have been done, then you can do April and May, but you can't go back and do February."

With my programer hat on:

It's easy to see that Sage stores the date the last depreciation was posted for any given asset as part of that asset's record. What I think it does, therefore, is perform a simple comparison of the month part of that date with the month for which the month-end is being processed:

If the month-end is more recent than the month of the last posting, post another month's depreciation.
If the month-end is NOT more recent than the month of the last posting, don't.

(I'm assuming it does something similar with prepayments and accruals).

What it perhaps should (and possibly could) do is as you questioned, Rob: It would be much better if it determined that if the last time month-end was processed was (say) three months ago, then it should process the transactions for the intervening months as well.

Another quick test shows that if you add an asset *after* the month-end has been run (or even several month-ends) - ie it's in the accounts, but you've forgotten to add it to the asset register - it's possible to go back and re-process the month ends from the point it was added, and the depreciation for that asset will be posted for those months you re-process. (This makes sense given the above logic). If it posted transactions for the intervening months, it could also include monthly transactions for any given asset from the date of the addition.

(What I'd be inclined to do with an asset to be added late - if I actually used the asset register* - would be to manually work out and post the depreciation for the intervening months, and set the net book value when first setting it up; but the above would be so much easier).

* I don't like it because it means one depreciation journal for each asset each month - with a lot of fixed assets, that's a lot of journals. I prefer a spreadsheet; work out the figures at the start of the year and set up one twelfth of the total depreciation for each category as a recurring entry, and then forget all about it until there's an addition or a disposal, or until the next financial year, whichever is soonest.