A new employee dress code unveiled by J.P. Morgan is meant to ease the strict rules common in banking, but raises a quagmire for women who want to appear professional while dressing down.

The U.S. investment bank’s new, more relaxed dress code has already been largely embraced by its management — Chief Executive Jamie Dimon is seen without a tie as often as he is pictured with one, as a recent appearance in London showed.

To be sure, Wall Street isn't morphing into Silicon Valley — where J.P. Morgan hatched the idea. Business casual, as J.P. Morgan wrote in its dress code, does not mean you should dress at work as if it were Saturday.

The dress code, reminiscent of a far more specific one issued by UBS in 2010 banning lunchtime garlic consumption and colorful or visible underwear, institutionalizes a policy that is already informally in place, J.P. Morgan said.

For men, the bank’s decision to no longer require a business suit has pretty straightforward implications: wear a jacket and open-collared shirt, or even a polo shirt in a more relaxed setting with no client meetings scheduled. 

Tight, Revealing, Low-Cut?

For women, the addition of wardrobe options like capris, open-toed shoes and even, with prior approval from a manager, jeans for staff who are not facing clients can present a decision-making process fraught with anxiety.

A receptionist was reportedly sent home last month after refusing to wear two- to four-inch heels as required by an appearance rulebook set up by an outsourcing firm hired by auditing firm PriceWaterhouseCoopers in London.

How much skin to expose is especially difficult, in a profession still defined as largely male and where women have struggled to make inroads in the top echelons. A line in J.P. Morgan’s code banning «distracting, tight, revealing or exceptionally loose or low-cut clothing» is surely overwhelmingly aimed at women.

Sheer Blouses, Stylish Hair

The emergence of sheer blouses in workplace fashion and a reference to unprofessional hairstyles — UBS' 2010 guidelines said that long hair should be kept neat and stylish — is also a potential minefield as ombre, dip-dye and now sombre hairstyles take off. 

As Wall Street Journal style maven Christina Binkley writes, even if capri pants are permitted under the bank’s new dress code, you still probably wouldn't want to wear a boldly-colored or floral-patterned pair to work – banking is still a highly conservative industry where a careful appearance counts. 

Barclays provided a textbook example of this last year, when chairman John McFarlane banned flip-flops for Canary Wharf staff including those of BarclayCard, who enjoy a more relaxed dress code than that of Barclays' client-facing staff.

Be Like Nicola

It's not uncommon for female professionals – from meteorologists to first ministers – to be criticized for what they wear, and the smart approach for women is to err on the safe side of wardrobe options.

If you are a female banker, it is best to define and select a new, more relaxed wardrobe around items that can be used interchangeably, minimizing decision time in the morning. Yes, this can mean ordering, say, 15 identical blouses at once, or buying the same item in several colors. 

Swiss Conservatism

UBS's overly zealous dress code, which famously made headlines in 2010 when it asked staff to stick to neutral, flesh-colored underwear, was never implemented. Today, retail branch staff in Switzerland have a choice of accessories such as a scarf, broach or tie to augment their outfit, a spokeswoman said.

Neither the Zurich bank nor its competitor Credit Suisse has a formalized dress code for all staff, leaving the decision instead to staff on what is appropriate or not. For relationship managers in Credit Suisse's flagship offices on luxury Bahnhofstrasse, a suit and tie remains de rigeur. For staff in back-office offices like Credit Suisse's Uetlihof or UBS' Opfikon sites, rules are looser.

«We leave it up to the individual employee,» UBS said, while a spokesman for Credit Suisse noted that style rules are something of an «unwritten law» between the bank and staff.