When to Upgrade

[Ellpee]

I'm working in Office 2010, so am already a couple versions behind, but so far so good as to backward compatibility. Some of my small list of mom'n'pop customers, though, are already using 2013 or Office 365/2016. Since I only dabble in this part time on an on-call basis, wondering how long I can put off the expense of upgrading to one of the newer versions. When is my procrastination going to bite me, and how?

[Micron]

So this is just an opinion. I'd still be using 2007 if it hadn't been for a pc loss, but then again, I'm not building for anyone. Older db's can have issues opening newer ones because of unsupported features - many of which are often not required. but anyone who has a newer version should be able to operate anything you build in an older version. One of your drawbacks is that you don't know how it looks when it gets 'transformed' by the newer version. Then some will say that by not upgrading, you expose yourself to some liability because older versions are no longer supported by M$, so any issues caused by vulnerabilities become your problem. Aside from any technical concerns, how will your potential customers view you as a prospective supplier if you fail to upgrade? They might consider this to be an indicator of your seriousness, to say nothing of what concerns they might have about those vulnerabilities.

[isladogs]

You should always do development work in the earliest Access version in use by your clients.
So if those clients use a mixture of A2010, 2013 & 2016, then you should continue to develop in 2010.

As micron has already said, users of later versions will still be able to run your app.
That is unless it contains deprecated features like pivot charts.

However the converse may not be true.
Problems can occur if you develop in a later version than your users are running.