It recently came to our attention via a client that the TTB does make market purchases of products to confirm the products are indeed what they say they are i.e. the alcohol content is specified correctly and/or the formula stated is what the actual product is.

To that end, we just wanted to remind you that COLA’s do need to be obtained for various changes in alcohol content, appellation changes, etc. Here is a link to a great article by the TTB on allowable changes.
https://www.ttb.gov/labeling/allowable-revisions

Those with formula-based products should also be very careful about any deviations made from the approved formula.

Those selling products that are under 7% ABV that do not require a COLA for sales, should also be sure that the products are testing under 7%, and for those over 7% you should be aware of the variations in ABV you are allowed from the level on the COLA.
https://www.ttb.gov/labeling-wine/wine-labeling-alcohol-content

We are not experts in this side of the business but we do suggest you or your team brush up on the details via the resources at TTB.

https://www.ttb.gov/wine/wine-faqs
https://www.ttb.gov/distilled-spirits/distilled-spirits-faqs
https://www.ttb.gov/formulation