TechUK - which represents more than 850 companies - also demanded rules to allow more skilled technology workers into the country.
"You've got to make sure the UK becomes a hub for digital skills," said TechUK chief executive Julian David.
The proposals will be presented to ministers on Tuesday.
Mr David said current options for migrating digital works - such as a special Entrepreneurs' Visa to help start-ups - was not going far enough.
"My members tell me it helps, but start-ups find it difficult to plot their way through the bureaucracy and the cost."
Bigger companies, he said, complained the process took too long.More than London
Mr David praised the efforts of organisations like Tech City UK, the government quango helping technology start-ups in the Silicon Roundabout area of east London.
But he said the digital economy must be a concern for the whole country.
"We've got fantastic capability in clusters around the country.
"When you look at places like Cambridge, there's a pattern of success there for growing digitally-focused, very large, very successful companies such as [chip maker] Arm Holdings."
As part of its manifesto for the next government, TechUK has said it wants a Cabinet-level minister representing the interests of the digital economy.
"The next government should ensure there is cabinet-level leadership to develop and execute a single digital strategy that rolls up the digital economy, digitalisation of government and digital inclusion," the document reads.
"Other systemically important policy domains have a clear departmental lead and a strong voice at the Cabinet table - it is time the full significance of digital is recognised in the same way."