A cost centre is broadly defined as a department to which costs are allocated but that does not produce revenue for the business.
When a lawyer works in private practice as a fee earner they are revered as the money-making engine driving the machine forward, a definite profit centre. Lawyers here can point to their tangible contributions to the firm in the form of billable hours and attributable business wins/relationships. Congruently fee earning associates and more notably partners are held in high esteem and remunerated upon their evidenced contribution to the firm.
The phrases both profit and cost centre have questionable conceptual efficacy. Peter Drucker who originally coined the term profit centre later recanted, calling it "One of the biggest mistakes I have made". Asserting that there are only cost centres within a business, and “the only profit centre is a customer whose cheque hasn’t bounced”. Nonetheless the fear that hiring an in-house lawyer will cost your business money rather than saving it or even producing it is one which has stymied the growth of in-house legal teams for years.
As a newly qualified lawyer in London at a top city or US firm the amount you are earning is significantly higher than it would have been only a few short years ago. The US firm’s entry into the London market and their willingness to offer pay parity with New York coupled with the frankly terrible GBP to USD exchange rate in recent years has led to bumper pay days for those associates at the top US firms and started a war for top talent.
The magic circle, keen not to be left out decided this year that they were tired of losing some of the best of the Oxbridge crop to US firms over money and decided to close the gap, starting lawyers on £100,000 or more as soon as they qualify. When Bingham McCutchen first broke through the £100K barrier for NQs in around 2012/13 they were trailblazers, how was it economically viable for them?! many laughed at the prospect of junior lawyers being paid so handsomely. Things didn’t turn out so well for Bingham but no one is laughing anymore as the pay packet is now the standard for associates at top tier firms.