The firm’s analysis of annual reports, corporate websites and other social responsibility reports, shows a steady increase in tax transparency across big business.

In 2012 just 32 firms in the FTSE 100 provided information on issues such as their attitude to tax planning and relationships with tax authorities. The number increased to 49 in 2013, and has now risen to 56, according to the most recent 2014 data.

Andrew Packman, tax partner at PwC, said: ‘Corporates recognise that people want to know where the company stands on tax. Already this year two tax questionnaires have been sent to the FTSE 100, one from an investor, the other from an NGO.

'The interest in tax is undeniable and it’s helpful to be able to point interested parties to existing public disclosures.’

PwC’s report suggests that there is no generic approach regarding what is disclosed and how this is done, as this depends on the needs of stakeholders, but says ‘the transparency tide is going in one direction’.

As part of this, the firm has identified an increased focus on tax risks, such as whether tax strategy is reviewed at board level. Fifty firms now set out their tax risk and governance procedures, 13 more than the previous year.

‘It’s also become more common for companies to quantify all the taxes they bear and generate – the total tax contribution – which is now published by 40 firms, up 16 on 2013,’ Packman said.

However, with the proposed OECD Base Erosion and Profit Shifting (BEPS) rules due to be issued this November, multinationals will be under further pressure to sort out their tax affairs. 

At the same time, the introduction of the Common Reporting Standard for tax transparency will force companies to disclose more details about their global tax arrangements, particularly use of offshore tax havens and profit shifting activity.