The state should receive your contribution information from the 529 administrator. So if you claim a deduction for a 529 contribution, they can check against their records. You don't need to provide anything except in the event of an audit.
VP, Research & Development
This information does not constitute tax advice and is provided for informational purposes only. Please consult your tax advisor, financial advisor, local taxing authority, and/or plan provider or sponsor for more information.