The European Commission in April presented a list of 19 online companies it said met the criteria for that designation. Amazon was on it, along with Twitter, TikTok, and services from Apple, Google, Meta and Microsoft.
From August 25, they will be required to follow rules set out in the European Union's new Digital Services Act (DSA), which aims to curb illegal internet content and disinformation.
One requirement is that they undergo an independent annual audit carried out on measures that the platforms and search engines use to fight disinformation, hate speech and counterfeits.
Another is that they open up their algorithms to the commission and offer approved researchers access to their data.
They also have to conduct risk analyses for illegal content on their services and come up with mitigation measures.
Those appearing on the EU's list of very large online platforms or search engines reached or surpassed a threshold stipulated in the DSA of 45 million active monthly users in Europe.
But an Amazon spokesperson said "the DSA was designed to address systemic risks posed by very large companies with advertising as their primary revenue and that distribute speech and information".
While Amazon agreed with that goal, it argued that "Amazon doesn't fit this description" as its revenue comes from retail sales, not ads, and "therefore (we) should not be designated" as a very large online platform (VLOP).
"If the VLOP designation were to be applied to Amazon and not to other large retailers across the EU, Amazon would be unfairly singled out and forced to meet onerous administrative obligations that don’t benefit EU consumers," the spokesperson said.
The US company says it has already implemented measures to protect customers from illegal products, independently of EU obligations. Those measures cost it $1.2 billion in 2022, it said.
Amazon's legal challenge follows one lodged last month by the German online retailer Zalando over its VLOP designation.