Banks like Barclays Capital, Deutsche, and Morgan Stanley have some of the biggest tax teams in the City. However, what these teams do exactly is the subject of some secrecy.

“Publicity of these businesses just doesn’t help,” says one headhunter specialising in the area. “These things are designed to reduce tax: anyone who writes about them is drawing attention to that.”

Faced with this lack of cooperation, we’ve been able to glean that banks’ tax teams are predominantly occupied with trading tax liabilities (AKA ‘capacity’). This takes various forms:

• Principal trading – trading banks’ own tax liabilities.

• Agency trading – trading clients’ tax liabilities.

• Match booking – matching one client’s tax liabilities with another’s tax breaks.

Business takes place internationally, with tax traded across jurisdictions. It’s very (very) lucrative: Roger Jenkins, who heads Barclays’ 70-or-so-strong business (and is also chairman of its Middle East operation, among other things), reportedly earned £40m last year.

If you aspire to work in tax structuring, the good news is that you now know it exists, which is apparently half the battle. Banks’ recent large losses also mean they have plenty of spare tax capacity to trade, and new players are said to be looking to boost their teams or move into the business.

“These people are not necessarily tax specialists,” says Talal Lashab, a recruiter focusing on tax structuring at Huxley. “They can also be mathematicians/quants or purely execution focused.”

The bad news is that, with the exception of Barclays, tax teams tend to be very small, and as noted you’ll probably have a problem finding out much about them.

Equally, banks that are in receipt of money from governments may yet find their tax structuring capabilities frowned upon – which could be one reason why Jenkins was instrumental in helping Barclays raise money expensively from Middle East investors instead.