The 23-year-old centre-back has a clause in his contract meaning that any bid over £100,000 will be accepted. QPR are believed to have bid between that amount and £200,000.
Chesterfield accept QPR bid for Evatt
"The lad is on holiday at the moment," said QPR chairman Bill Power, whose side have been looking for a new centre-back all summer.
"He is back on Friday and hopefully we will be able to sort everything out from there."
Evatt has been a key performer for the Spireites since joining two years ago, and he has been linked with a number of bigger clubs in the past year.
Just a couple of weeks ago QPR made an enquiry for Iron centre-half Andy Butler. But they were put off by the fee United felt Butler was worth.