Northern Ireland's shopping centres reported a slump in visitors of nearly 4% during October in the worst fall of the UK nations, according to a survey today.
Information body Springboard and the Northern Ireland Retail Consortium also reported a footfall drop across retail in general of 2.1%.
And while shopping centre visitors were down at the highest rate in the UK, high street footfall decline had slowed to 1.5%, shallower than the month before. And the retail vacancy rate increased from 14.1% to 14.3%.
Aodhán Connolly, director of the Northern Ireland Retail Consortium, said the falls reflected the need for reform of the business rates system here. A consultation by the Department of Finance into reform of the levy - one of the biggest overheads facing retailers - closes today.
Mr Connolly said: "There is little to be enthusiastic about in these latest footfall and vacancy results. We again have seen a decline in footfall which rounds off a six month streak of falling shopper numbers on our high streets and shopping centres."
"The shop vacancy rate in our town centres is similarly depressing with a small yet noticeable rise in empty premises.
The simple fact is that the cumulative burden on retailers has become too much to bear and retailers of all sizes are feeling the squeeze."
He said the system was particularly punitive in NI, where the highest level of business rates is 10pm in the pound more expensive than anywhere in Great Britain.
"The DoF's consultation on the future of rates closes today, and we are calling for fundamental reform because for our industry in NI it is a key priority.
"The retail sector is 12% of the economy in NI but pays a quarter of all business rates. That is both inequitable and unsustainable." He said that if rates were not reformed, shops would be lost - which would ultimately mean less rates revenue, resulting in less income for councils and Stormont departments.