The direct mail and PoP site produces material for companies including Lloyds TSB, Honda and Direct Wines.
FSC certification acknowledges Bezier's efforts to source paper from renewable and socially responsible sources.
Susan Steyn, business unit director at Bezier in Poole, said: "We are delighted to have achieved FSC accreditation. Paper use is essential in our business and we work hard to find environmentally friendly options.
"Now we can assure our customers that our paper and card has been sourced from responsibly managed forests."
Bezier chief executive Mark Shaw said: "The environment is very much at the top of everyone's agenda and as a group it is essential that we provide our customers with sustainably sourced products.
"The FSC accreditation demonstrates our dedication to this cause and we are working towards gaining accreditation at all of our manufacturing sites around the country."