Each year, the survey measures suppliers′ views on how the main water and sewerage companies perform and compare with each other.
It looks at ten different performance areas, including contract procurement, contractual approach, impact on the supply chain and communication.
It is the seventh time in eight years that Northumbrian Water, which Essex & Suffolk Water is a part of, has topped British Water′s annual list for supplier satisfaction.
Northumbrian Water came out on top, with an average overall score of 7.7 out of 10. It also scored the highest in nine out of ten of the categories.
Stephen Whaley, Essex & Suffolk Water′s Contracts Procurement Manager, said: "This is another great result with suppliers choosing us as the number one water company to work for again.
"It demonstrates the hard work that we have put into building strong, working relationships with our suppliers in order to deliver an excellent service to our customers."
British Water, the trade association for the UK water industry supply chain, represents the industry collectively to government, regulators, other institutions, customers and the media.
The Essex & Suffolk Water suppliers who take part in the survey, range from framework capital contractors and consultants, to chemicals suppliers, distribution materials suppliers, maintenance, waste and operational contractors.