Accommodation is needed for at least 2,000 Ukrainian refugees from December when the lease on Tallink's Isabelle cruise ship expires.
The Social Insurance Board (SKA) is now looking for new accommodation.
Every Ukrainian refugee who arrives in Estonia and expresses a wish to stay can receive shelter, SKA's Director General Maret Maripuu said on Wednesday.
"The coming winter could see the number of refugees arriving here multiply. We are therefore looking for a solid partner to work with to accommodate people in the very short term," she said.
The agency's new tender states providers need to be able to accommodate at least 2,000 people and they can be dispersed among four locations.
Refugees must have access to public services and be able to provide space for children, a medical center, counseling sessions and other services.
The initial contract is for six months but could be extended for a further two.
Since the beginning of Russia's full-scale invasion, Estonia has provided temporary accommodation for 20,000 refugees. Currently, 3,500 are being housed by the state and 2,000 of them are on the Isabelle ferry.
The state has paid out €30 million for short-term accommodation so far.
Editor: Mirjam Mäekivi, Helen Wright