Most major U.K. banks, with the exception of HSBC Holdings Plc, reported details of their gender pay gaps ahead of the April 5 deadline by which they are required to do so.

Virgin Money Holdings (UK) Plc reported a mean hourly rate gender pay gap of 32.5% for the 2016 performance year. The bank says it aims to attain a 50:50 gender balance throughout the business by 2020, with a 20% tolerance. The group has an all-female top leadership with Jayne-Anne Gadhia as CEO and Irene Dorner as chair-elect.

Standard Chartered Plc reported a 2017 mean hourly pay gap of 30.4%, and a mean bonus pay gap of 57.1%. It attributed this to proportionally fewer women than men in roles where market rates of pay are highest and where a higher proportion of total pay is delivered as a bonus.

Lloyds Banking Group Plc reported a mean gender pay gap of 32.8% and a mean bonus gap of 65.2%.

Barclays Plc reported an ordinary pay gap of 14.2% at Barclays UK and 43.5% at Barclays International, which houses its investment bank, and a bonus pay gap of 46.9% at Barclays UK and 73.3% at Barclays International. The bank came under fire from U.K. House of Commons Treasury Select Committee Chair Nicky Morgan for the sharp difference between men and women's pay.

Royal Bank of Scotland Group Plc said that its mean gender pay gap was 37.2% and its mean gender bonus gap was 64.4%.

An HSBC Holdings Plc spokeswoman told Reuters that the bank will disclose its pay gap details ahead of the deadline.

Meanwhile, Morgan has written to financial firms prompting them to sign the Women in Finance Charter, a pledge for gender equality. Some global financial institutions are said to be stalling on signing up, which may be due to lengthy approval processes and cross-border issues.