Only around half of councils in England have made any payments to businesses from the £1.5bn rates support package.
A freedom of information request made by Gerald Eve found £700m of business rates relief is likely to remain unpaid when the deadline arrives, with only half of English councils paying out.
It asked all 309 councils in England how much they had paid out to local businesses. Of the 219 that replied, just 58% have started paying out anything, despite a deadline for concluding relief payments coming in less than two months.
Any surplus must be handed back to the government, short-changing businesses by about £700m, the consultancy said.