If Warren Buffett and Brazilian investment group 3G Capital back away from their proposed $23 billion acquisition of H.J. Heinz Co. , they'll have to pay up.

The reverse break-up fee - the amount that Buffett and 3G will have to pay Heinz if they can't close the deal - totals $1.4 billion, according to a regulatory filing on Friday.

Buffett's Berkshire Hathaway and 3G would each pay 50 percent of the fee, the documents said. The fee is roughly 5 percent of the deal value, which includes $5 billion in debt. That's largely in line with historical averages.

J.P. Morgan Chase & Co and Wells Fargo & Co committed to $14.1 billion in debt financing, according to the filing.

(Reporting By Olivia Oran; Editing by Nick Zieminski)