If you have had an independent assessment of your carbon footprint as a business, and an analysis of the specific impact of the products or services you sell, that enables whoever is buying from you to understand the impact of their spend.
When somebody commissions your service or buys your product, they are under more and more pressure to report on the impact of that spend, so that they can demonstrate they are making the most environmentally responsible choice. Having that verification of the impact means you can give them genuine, detailed insight - which makes their journey to net zero, and their understanding of the impact of their spend within their supply chain, much easier.