Standard Chartered Plc's probable expenditure on relocation to Frankfurt could amount to $20 million, CEO Bill Winters told Reuters.

Winters cited Germany's sovereign credit rating as a factor that sealed the bank's decision to choose Frankfurt over Dublin as its post-Brexit EU base, according to the Aug. 4 report.

He noted that "basic sales staff and relationship managers are already in situ across the continent," but that questions remain over where employees will have to be post-Brexit.

The $20 million cost of activating the German subsidiary would go toward the costs of converting it from a branch, Winters said, adding that March 2019 would be when capital, "in the hundreds of millions," would start flowing into the subsidiary, subject to the requirements of Bafin, the German banking regulator.