Something that you inevitably have to prepare once a year are your official reporting apart from the annual report. There are filings such as statistics, employee related (depending on your local legislation of course), but almost certainly there are tax reporting (or tax filings) you have to prepare and submit to tax authorities once a year. Yes, some are prepared once a month, others once a quarter, but there are almost always some tax filings you’d have to submit once a year and not more often.
The thing with tax filings prepared just once a year is that you might forget how one is done, what information is needed and whether everything is collected information wise or not. So I suggest you make yourself a list of actions you always do when you prepare the filings. This way you’d ensure that don’t forget anything, you have the course of actions to take.
Having a list of actions is something we almost always suggest you should have and there’s a reason for it. A list of actions is sort of a checklist ensuring that nothing gets forgotten, there’s a structure to doing things and as practice has proven, having structure when it comes to accounting, is never an unnecessary thing.