Vantastec Ltd, located in Ystrad Mynach, walked away with the prize after being declared winners by a panel of industry experts.
They fought off competition from the likes of CPD Bodies, Cumberland Platforms, Piaggio Commercial UK and Sortimo International to clinch the top spot.
The WhatVan? Awards is the flagship awards show in the Light Commercial Vehicles sector, showcasing the very best businesses and manufacturers within the industry.
This year's ceremony was held at the Hilton Bankside Hotel in London.
On winning the award, company Managing Directors Gareth Edwards and Colin Smith said:
“It is truly an honour to be receiving such a prestigious trophy.
“The WhatVan? Awards are so crucial for our industry, so to be shortlisted as finalists for two years running was enough of a compliment in itself.
“Now, to be named Converter of the Year – an award we have looked to win for so long – is really the icing on the cake.”
Vantastec Ltd is a specialist light commercial vehicle converter whose work includes temperature-controlled conversions, catering and coffee can conversions, animal transportation vehicles, bespoke tailored vehicles and much more.
The company was founded in 2006 and was based in Penallta before moving into a larger, 28,000 square foot facility in Ystrad Mynach in 2013.
Gareth and Colin continued:
“We started the business from our home offices with next to nothing. So to see how far we have come makes us incredibly proud.
“For 13 years, we have worked to create the best product available on the market. Whether that be coffee vans, refrigerated vehicles, animal transport, bespoke conversions or anything in-between.
“It is a credit to our amazing team of engineers and office staff. Without them, we wouldn't be where we are today.”