When you make your labels, you should be honest and as accurate as possible. But mistakes can happen, and it's OK if your labels aren't completely perfect; nutrition fact labels aren't designed to be perfect.
At the end of the day, the goal is to provide your customers with reasonable and useful information about what they are eating and drinking. So don't purposefully deceive your customers. That's very bad, for them and for you.
If your facts aren't perfect, you might hear from the USDA or FDA, but they generally won't make you reprint all your labels until you run out of the current batch. According to the FDA: "FDA is unlikely to take regulatory action for minor errors. However, such errors should be corrected during the next printing of labels."
Do Your Homework
You can minimize mistakes by doing research, sense checking your labels, and comparing them to similar products before finalizing them. Our database has thousands of ingredients, but you can also choose the "custom ingredient" option to include the information for the exact ingredient you use. Your food suppliers can usually provide this information if it isn't on the packaging.
Consider a Label Review
And if you're still not comfortable, consider having a label reviewed by a professional.