Just found out that the city we're in raised the sales tax again, the second time this year. Since we didn't know about the change, we've been charging our customers the lower rate for some time now.
How are we supposed to know when the tax laws change? We're a small business, just a few people here. Hiring a full-time financial professional would be way out of our budget. We're located in California, but a general strategy that would help businesses located elsewhere would be appreciated.
You have to have an accountant who would alert you on such things. It doesn't mean you have to hire a full-time accountant on staff, and not even a retainer (although you might want that).
But build a relationship with the accountant that deals with your tax returns, make sure he's aware of what your business is and does, and it would be his task to keep you informed on all the changes in a timely manner.
Another point of contact would be your local chamber of commerce. Also, I'm sure the city/county government has a mailing list or a site with news updates you can subscribe to.
You don't need a full-time accountant - just one you see every month or 2. You will save a lot more than you spend on their advice - they are the domain expert.