Dimon, who has previously said the firm would move as many as 4,000 jobs from the City, was accompanied by Daniel Pinto, chief executive of the corporate and investment bank.
A spokesperson for the bank said: “We appreciated hearing from the Prime Minister and her time today. While some uncertainty remains, we feel that the government understands the concerns of international firms such as ours, and the economy more broadly.
“We were grateful for better clarity on the government’s objectives in the Brexit negotiations,” the spokesperson added.
The US bank has committed to maintaining a large proportion of its UK workforce, although the exact number of jobs moved to the EU will ultimately depend on the trade arrangements agreed in Brexit negotiations.
Dimon said in July that the EU could force the bank to move more jobs onto its territory for regulatory purposes.
The JPMorgan bosses told May and Hammond about their plans to strengthen operations in Dublin, Frankfurt and Luxembourg, as well as bolstering existing branches in cities such as Paris, according to Sky News, which first reported the meeting.
May has previously told the City that barriers to trade after Brexit are “needless”, suggesting at a Bank of England conference she was confident a deal which preserves the current mutual market access could be struck.
However, City figures have become more nervous in recent weeks as talk of a “no deal” scenario has increased. The failure to agree a deal would create a sharp shock to many financial institutions.