A planned cut to business rate rises in England has been brought forward by two years to 2018 by the chancellor.
From April, rates will rise in line with the lower Consumer Prices Index (CPI) measure of inflation, not the Retail Prices Index (RPI).
The move is worth £2.3bn to businesses over the next five years, Chancellor Philip Hammond said.
But Adam Marshall, director general of the British Chambers of Commerce (BCC), said "more remains to be done".
He said the chancellor's decision would lessen the impact of rate rises on hard-pressed firms, but that wider questions remained over Brexit.
"Businesses will expect greater boldness from the chancellor – and more radical support for infrastructure and investment – once a Brexit transition period is secured," he said.
In his Budget speech, Mr Hammond said the move would help the UK's 5.5 million small businesses – which he said showed "extraordinary vibrancy and resilience" but "are feeling under pressure right now".
Business rates, a property tax based on rental values, were due to go up next year in line with September's RPI of 3.9%, while CPI was 3% that month.
Helen Dickinson, chief executive of the British Retail Consortium, which campaigned for the switch alongside the BCC, said the move to CPI was "hugely welcome and positive".
She said: "It's clear that the chancellor has listened to the retail industry and the growing chorus from across business and commercial life who have spoken up in favour of action to mitigate rising rates bills.
"Crucially, this relief will unleash investment that retailers want to direct towards the needs of their customers."