Revenue: £53.3m (-10%)
Net profit: 3%
This Egham-based audiovisual specialist recently opened its seventh UK office in Edinburgh, and also boasts a presence in Germany and China. In its year to 31 March 2017, ProAV - which has a 25-year relationship with Barclays Bank - saw revenue dip 10 per cent to £53.3m, although net profits widened from £1.5m to £1.6m. A "smart home space" project for John Lewis' flagship Oxford Street store is among the case studies displayed on its website.