The Association of Chartered Certified Accountants has called for the Scottish government to increase the audit threshold for charities.
Charities in England and Wales with annual incomes of £1m or more are required to complete an audit but the threshold is £500,000 in Scotland, and has not been updated since 2005.
The ACCA said audit fees paid by smaller charities were proportionately higher than those for larger charities.
“These findings came on top of feedback from ACCA members across Scotland that some charities were struggling to find an audit supplier,” the body said.
“Publicly available data analysed by ACCA experts, covering a sample of about 50 charities, showed that for those with a turnover under £1m who were subject to audit, the cost of the fee as a percentage of their annual income was on average 0.8 per cent.
“This is compared with 0.4 per cent for charities with an income over £1m.”
The Scottish Council for Voluntary Organisations said it welcomed ACCA’s support for a review to better understand audit issues.
Kirsten Hogg, head of policy and research at the SCVO, said: “Over the last few years we have increasingly heard from charities facing difficulty in accessing audit, due to a combination of rising costs and a decrease in firms offering charity audit services.
“At a time when charities are facing considerable financial challenges, and a lack of resources sees staff and volunteers under considerable pressure, these difficulties present a significant challenge.
“We welcome ACCA’s support for a review to better understand these issues, and to develop sensible solutions that work for both charities and the accountancy industry, while ensuring that charities continue to meet appropriately high standards of governance and regulation.”