The National Health Service has booked a financial surplus of £2.1 billion for 2012-13, remaining flat with that last year.

According to the National Audit Office, the figures show that there was sufficient money in the health service "to make ends meet". 

However, it also highlights "a substantial gap" between those trusts with the largest surpluses and those with the largest deficits.

This variation was also seen between local health economies, with differences most marked in London, where PCT clusters in parts of west London had some of the largest surpluses and outer north-east London one of the largest deficits.

At first glance, the number of foundation trusts and NHS trusts reporting a deficit dropped from 31 at the end of 2011-12 to 25 at the end of 2012-13.

However, a closer look reveals that trusts may be balancing their books only because they are getting extra local cash from health authorities; without this, 43 trusts would have been in the red in 2011/12 and 44 this year, the NAO said.

And while the surplus booked seems to suggest that the financial performance of the NHS is stronger this year, "there are signs of increasing pressure", it warns, as shown by the decreasing average EBITDA margin (earnings before interest, tax, depreciation and amortisation as a percentage of income) over the last three years.

Nevertheless, according to the NHS Confederation, the fact that the NHS has managed to deliver a surplus "is a real testament to the sheer hard work by NHS organisations and their staff, especially given the challenging targets set".

The group does, however, stress that “increasing numbers of NHS organisations are facing extreme financial difficulty", and that for a more stable financial footing "substantial changes to the way that services are provided and how and where people are cared for", are required, with a greater investment in primary and community services in particular. 

NHS finances also hit the headlines earlier this month when NHS England warned of a funding shortfall of £30 billion by 2021.