Through his service Adam has shared so much knowledge and given me great confidence in fulfilling my goals as a collector. Through his consultation service he teaches me about rare bookstores, auctions and buying strategies. And through the verification service I now have the confidence to invest in JK Rowling signed books, something I never thought would happen based on the scary world of counterfeits and scammers. Adam truly is the best in the business.

- David (Harry Potter book collector)

In a market flooded with forgeries, it's never been so important to check the authenticity of anything signed. Adam Houston has a remarkable knowledge of Rowling's signature and is able to identify the subtle details and changes over time - right down to the type of pen that was being used on specific dates. I won't catalogue or sell anything in our specialist Harry Potter & Library Auction without provenance, a statement from our vendor, and, importantly, without consulting Adam for his expert opinion. Adam has given me peace of mind with signed material on numerous occasions over the last few years. His authentication service is a superb idea and will help combat the fraudulent trade of fake signatures being peddled by unscrupulous sellers. It's just what the collecting community needs. I will always be delighted to include anything accompanied by one of his certificates in our specialist sales.

- Jim Spencer (Hanson’s Auctioneers)

A truly fantastic service from start to finish! I had my book fully authenticated and from first making contact Adam was friendly, professional and knowledgeable. All I had to do was supply high quality images and the remainder of the process was made very easy. The quality of the certificate is second to none and now takes pride of place with my signed book. I'd confidently recommend Adam's service to anyone considering or already collecting Harry Potter books. Cheers Adam!

— Rob (Harry Potter book collector)

“Adam has long been my first choice when double-checking on J. K. Rowling signatures. Not only is his instinct sharp, it’s complemented by a deep understanding of his subject and an impressive and constantly-growing database of Rowling signatures, both real and fraudulent.”

— Damian (Harry Potter book collector)