The government's Coronavirus Job Retention Scheme (CJRS) begins winding down from 1 July.
Around 1.5 million workers are still on furlough and the change will affect thousands of firms across the country.
Furloughed staff will continue to receive 80% of their wages, but employers will now pay 10% of that amount.
However, according to the Institute for Fiscal Studies (IFS), the bill for employers keeping a member of staff on the scheme will rise significantly, putting jobs at risk.
The IFS said the cost would rise from £155 per month, which covers costs such as national insurance contributions (NICs), to £322 in July and £489 in August and September.
Tom Waters, Senior Research Economist at the IFS, said: 'The furlough scheme does need to be wound down as the economy recovers, rather than attempting to keep every job on life support. But this does mean that some will end up unemployed.'
Further details of changes to the CJRS can be found here.