NHS organisations in London were issued with a 21-point checklist earlier this year to assist them in keeping their surpluses within a level acceptable to the Department of Health, HSJ has learnt.

The advice in the checklist - sent to all NHS trust and primary care trust finance directors in April - includes writing off bad debts and dilapidation of buildings, counting expenditure on hearing aids as revenue rather than capital and making provisions for expenses and claims not yet incurred but which could be shown to relate to 2007-08.

Many treatments in the list require accountants to estimate likely costs rather than measurable expenses. They would all have the effect of reducing an organisation's reported surplus. A number were highlighted earlier this year when HSJ reported that their use was enabling some NHS organisations to deflate their surpluses by over a third.

Three of the four biggest corrections auditors made to NHS accounts this summer involved treatments in the checklist and two of the four were in London.

See Pick and mix accounting clouds surplus predictions

In the letter that accompanied the list, NHS London director of finance Paul Baumann said: "To assist PCTs and trusts achieve their control total [we have] identified a number of measures which may assist in managing the year-end."

He warned: "The SHA's control total of£300m has been confirmed by the DH as a 'ceiling' for the financial year 2007-08." He said there was a clear expectation that individual organisations "will not exceed their control total, ie, have a higher actual surplus at the year end".

Mr Baumann added: "Delivery of financial performance will be measured against the final out-turn in audited final accounts."

An NHS London spokesperson said all the treatments in the checklist were "standard accounting practice".