The German lender has established a working group to assess the consequences of a possible “Brexit” following an in/out referendum, which David Cameron has pledged to hold by 2017.
A spokesman for the bank told the BBC it was “early days and no decisions have been made”.
The Financial Times said it was the first financial giant to formally review its position and it will consider whether to move some parts of the business back to Germany.
According to the company’s website it employs more than 8,000 people in the UK, including at its office in London.
The news comes after senior figures at building equipment firm JCB suggested the UK would not suffer any adverse effects from leaving the EU.
Lord Bamford, a Tory donor, backed the idea of Britain leaving the European Union, telling the BBC the country could exist “peacefully and sensibly” on its own.
And JCB chief executive Graeme Macdonald told a newspaper that Britain should leave the EU unless it reforms, playing down fears that an exit could hit exports to the Continent.
He told the Guardian: “I really don’t think it would make a blind bit of difference to trade with Europe (if the UK left an unreformed EU).
“There has been far too much scaremongering about things like jobs. I don’t think it’s in anyone’s interest to stop trade. I don’t think we or Brussels will put up trade barriers.”