The company forecast that shipments of this category of devices would grow to 351.6 million units in 2024, with a CAGR of 11.2% from 2019 to 2024.
Most of the growth was seen in markets where trade-ins served as a means for users to upgrade, with many premium flagship models being dependent on this kind of transaction.
IDC said vendors like Apple, Samsung and Huawei had their own trade-in offers which were much more aggressive compared to other channels. Telcos were using bundled plans along with trade-ins to convince users to upgrade.
"Refurbished and used devices continue to provide cost-effective alternatives to both consumers and businesses that are looking to save money when purchasing a smartphone.
"Moreover, the ability for vendors to push more affordable refurbished devices in markets where they normally would not have a presence is helping these players grow their brand as well as their ecosystem of apps, services, and accessories."
Will Stofega, IDC's program director for Mobile Phones, said: "Although the COVID-19 pandemic has posed challenges for secondary market participants around able-bodied workers and logistics, most of the industry has been able to satisfy demand for refurbished smartphones.
"Once the pandemic begins to fade, those that were able to invest in technology will be well-poised to prosper during the recovery."
The research firm defines a refurbished smartphone as "a device that has been used and disposed of at a collection point by its owner. Once the device has been examined and classified as suitable for refurbishment, it is sent off to a facility for reconditioning and is eventually sold via a secondary market channel.
"A refurbished smartphone is not a 'hand-me-down' or gained as the result of a person-to-person sale or trade."