Ask a Business Lawyer. Get Business Law Questions Answered ASAP.
Your understanding is correct. There is no requirement under federal or state law in the US that invoice numbering be consecutive or uninterrupted. They can anything the vendor chooses.
If this answer is responsive to your question, please accept it. That is how we are compensated. It would also be appreciated if you provided feed back on your view of the answer. Finally, if the answer was especially helpful you can provide a bonus. If I can be of further assistance or you have other questions in the future you can ask for me and reach me at this site.
This communication is not intended as legal advice. A local attorney should always be consulted for legal advice. No client/attorney relationship is intended or created by this communication.