A fifth of software used by London businesses is unlicensed, costing the software industry £149m a year, according to a report published today.
The London crackdown follows earlier campaigns in Glasgow and Manchester as part of a BSA programme to raise awareness about the impact of software piracy on the local economy.
Software piracy, said the BSA, is a drain on technology and creative companies, which employ 500,000 people and create 20% of new jobs in London each year.
Software piracy in the whole of the UK reached a record high of 27%, worth £1.49bn in losses to the software industry last year, a study by IDC revealed.
According to the study, 41% of software in use around the world is unlicensed, with an overall loss to the software industry of £43bn.
The BSA will contact more than 1,000 London-based companies to encourage them to return self-audit forms to ensure the software installed is licensed appropriately and cost-effectively.
At least one London company has been forced to pay a settlement to software suppliers for using unlicensed software as a result of the BSA's investigations.
The BSA said other firms face similar fines based on how much unlicensed software they are using and how long they have been using it, and company directors could be personally liable.
Alyna Cope, BSA-UK spokesperson, said the organisation wants to promote the value of software and educate business on how to manage it better.
The BSA campaign is aimed at helping businesses save time and money in the economic downturn and reduce the risk of legal action, said Cope.