Birmingham boss Garry Monk has made one summer signing so far
Birmingham City need to meet certain "requirements" laid out to them by the English Football League before they can add to their squad, the EFL have said.
The club are reportedly the subject of a transfer embargo, but neither the EFL nor the club have confirmed this.
Blues have not made a new signing since Union Berlin left-back Kristian Pedersen joined on 25 June.
When asked if new arrivals were likely, Monk told BBC WM 95.6: "We're still waiting for confirmation from the EFL."
The Championship club's boss added: "I'm waiting to hear, like everyone else, to see what the outcome is going to be.
"We need to hopefully have that [clarification] sooner rather than later. Yes of course [it's frustrating] but that's something that's out of my hands.
"In the meantime I have to just do what we're doing and get us ready for the start of the season."
An EFL spokesperson told BBC Sport: "The EFL has been in regular contact with the club throughout the summer and set out on 13 July our requirements in respect of the basis upon which the club would be able to make additions to Garry Monk's squad."
Monk was named as Birmingham manager on 4 March and steered them to a 19th-place finish last term, securing their survival in the Championship on the final day of the season.
Their 2018-19 campaign gets under way at home to Norwich City on Saturday.
Source: bbc.com