This work allocation may be rotated after a set number of years to mitigate the risk of over-familiarity.
Work performed by each auditor is reviewed by the other, in most cases by exchanging audit summary reports.
The critical issues at group level, including group consolidation, are reviewed jointly and there is joint reporting to the legal entity's management, its audit committee, a government entity, or the general public.
In France the joint audit system is obligated by law for PIE's.
[1] Joint audits are used internationally, including in India, Denmark, Germany, Switzerland and the UK.
The benchmarking that takes place between the two firms raises the level of service quality.
A recent report produced by consultants London Economics for the European Commission highlighted that France and Denmark (two countries with joint audits) are the two least concentrated audit markets in Europe.