Christian Horner admits there is no guarantee Red Bull will not breach Formula 1's new budget cap for the second year in succession.

After being found guilty of a 'minor' overspend following a high profile controversy last year, the reigning champions received a $7 million fine and a 10 percent reduction in car development time.

Dan Fallows, previously Red Bull's aerodynamics boss but now technical director at big-spending midfield rival Aston Martin, doubts the penalties will slow the energy drink-owned F1 team too much.

"They finished last year very strong," he is quoted by the Dutch publication Formule 1.

"This year there are some rule changes, but they are not that big. So they're obviously in a very, very good place.

"Limiting wind tunnel hours definitely hurts and they will feel it to a certain extent," Fallows added.

"But they have a lot of experience with these rules, so I am confident that they will minimise the consequences of that penalty."

F1 CEO Stefano Domenicali this week admitted he is uncomfortable with how long the FIA took to rule on Red Bull's alleged overspend last year amid wild speculation.

And now Red Bull boss Christian Horner admits it cannot be ruled out that the team will once again fall foul of the budget cap's complex rules.

"You can never be 100 percent sure," he said, "especially after all the aspects that caused us to go over in 2021.

"But don't forget that it was the very first year in a series of very complicated regulations, so we are confident that we should stay comfortably within the limit," Horner told Auto Motor und Sport.

And, like Fallows, he doesn't expect the overspend penalties to hurt Red Bull too much in 2023.

"For 2022, the amount of development we did, and especially the crash damage we had, was significantly less," said Horner.

"Until you get the certificate, nothing is 100 percent," he added. "But I'd be very surprised if we didn't stay completely within the limit."