In January 2020 the BBC Shared Data Unit reported empty businesses costed UK taxpayers £1bn a year, prompting calls for urgent reform of the system.

Some councils lose out on millions of pounds of potential business rates income through a tax relief on empty properties, BBC analysis shows.

A local authority mayor in northern England said the money "added up to a lot" and the system was unfair.

The Treasury said it would announce a review of business rates "in due course".

Experts say the current system pits local authorities - which want stable income - against businesses.

The Shared Data Unit makes data journalism available to news organisations across the media industry, as part of a partnership between the BBC and the News Media Association. Stories generated by the partnership included:

• Newcastle: Chronicle Live: Empty businesses cost the North East more than £137m in lost taxes 16 January 2020
• Eastern Daily Press: Empty shops in Norwich to cost YOU £5m in 2020 16 January 2020
• Luton Today: Luton loses out on 2% of business rates each year through empty shop units 16 January 2020
• Ilford Recorder: Revealed: How much do empty businesses in Redbridge cost the taxpayer? 16 January 2020
• Romford Recorder: Revealed: How much do empty businesses in Havering cost the taxpayer? 16 January 2020
• Dorset Echo: £14 million business rate income lost due to empty shops in Dorset 16 January 2020
• Bridport & Lyme Regis News: £14 million business rate income lost due to empty shops in Dorset 16 January 2020
• The Argus: Brighton council losing millions in unpaid business rates 16 January 2020
• The Argus: Many shops lie empty in Brighton and Hove 16 January 2020
• The Argus: Academic says empty shops are 'slippery slope' for the High Street 16 January 2020
• News & Star with The Cumberland News: Empty shops cost Cumbrians £20m 16 January 2020
• The Yorkshire Post: Empty building owners ‘exploiting loopholes’ to deprive councils of millions 16 January 2020
• Yorkshire Evening Post: Empty Leeds businesses cost taxpayers more than £100m in five years 16 January 2020
• Plymouth Live: The £2.7m a year cost of Plymouth's closed down businesses 16 January 2020
• Worcester News: Hidden cost of empty shops: Lost business rates costs us millions 16 January 2020
• Malvern Gazette: Hidden cost of empty shops: Lost business rates costs us millions 16 January 2020
• Bolton News: Business rates cost Bolton council millions in relief for empty units 16 January 2020
• Portsmouth: The News: Almost £2.5m lost every year due to empty businesses in Portsmouth 16 January 2020
• Lancashire Telegraph: REVEALED: The cost to taxpayers of business rates relief in East Lancashire 16 January 2020
• Northampton Chronicle & Echo: Revealed: Northampton empty businesses cost taxpayer more than £18m over the last five years 16 January 2020
• West Bridgford Wire: Revealed: The cost of empty businesses to the Nottinghamshire boroughs and districts 16 January 2020
• Blackpool: The Gazette: REVEALED: The millions lost to our vital Blackpool Council services through the tax relief on empty shops 16 January 2020
• Berkshire Live: The true cost of empty shops in Slough, Reading and Berkshire 16 January 2020
• Hereford Times: Hidden cost of empty shops: Lost business rates costs us millions 16 January 2020
• Northamptonshire Telegraph: Empty businesses cost Northants councils millions 16 January 2020
• Bromsgrove Advertiser: Hidden cost of empty shops: Lost business rates costs us millions 16 January 2020
• Welwyn Hatfield Times: Are business rates harming or helping shopping centres in Welwyn Hatfield and Hertsmere? 16 January 2020
• Business Matters: Reform demanded as empty business rate costs UK £1BN 16 January 2020
• Hartlepool Mail: Empty business premises cost Hartlepool tax payers more than £4million over five years - with more predicted to come 16 January 2020
• Northumberland Gazette: Empty business premises cost Northumberland tax payers more than £4million over five years - with more predicted to come 16 January 2020
• The Shields Gazette: Empty business premises cost South Tyneside tax payers more than £7million over five years - with more predicted to come 16 January 2020
• Liverpool Echo: Regeneration brings million pound boost to Merseyside region that badly needs it 16 January 2020
• Gedling Eye: Empty shops and businesses in Gedling borough cost taxpayer more than £2m over the last five years 16 January 2020
• Business Live: Empty shops and other businesses cost SW taxpayers £30m a year 16 January 2020
• The Bucks Herald: Empty shops in Aylesbury have cost the tax payer nearly £11m over the last five years 17 January 2020
• Leamington Spa: The Courier: Taxpayers in Warwick district paying millions to cover lost business rates 17 January 2020
• Swindon Advertiser: Empty shops ‘cost’ council nearly £2m this financial year 17 January 2020
• York: The Press: York misses out on £3m in business rates - amid calls for new rules 17 January 2020
• Lynn News: Empty units in West Norfolk costing taxpayers £1m per year 17 January 2020
• Harrogate Advertiser: Empty business premises in Harrogate have cost tax payers almost £9million over five years 17 January 2020
• Surrey Live: Empty Surrey businesses cost taxpayer more than £85m in hidden rates losses 18 January 2020
• Bristol Live : How much empty premises are costing Bristol taxpayers 18 January 2020
• The Northern Echo: Empty business units cost taxpayers £137m in five years 18 January 2020
• Dudley News: Empty Dudley business premises cost taxpayer £25million 18 January 2020
• Watford Observer: Empty business units costing taxpayers millions in South West Hertfordshire 20 January 2020
• Sunderland Echo: Empty business premises cost Sunderland tax payers more than £14million over five years - with more predicted to come 20 January 2020
• Lancashire Post: Preston losing up to £3.2m a year because of empty shops 20 January 2020
• Bournemouth Daily Echo: £14 million business rate income lost due to empty shops in Dorset 21 January 2020
• Essex: Daily Gazette: More than 200 shops and offices across Colchester are lying empty 21 January 2020
• Epping Forest Guardian: Epping Forest loses almost £5m in five years from empty shops and offices 21 January 2020
• Rugby Advertiser: Think Rugby is full of empty shops? It's doing better than the average English high street 22 January 2020
• Lincolnshire Live: The hidden £30m cost to Lincolnshire taxpayers 27 January 2020
• Eastbourne Herald: Empty shops in Eastbourne are losing more than half a million pounds a year 4 February 2020
• Worthing Herald: Six-figure cost of empty business units in Worthing, Adur and Arun revealed 4 February 2020
• Scarborough News: Empty business premises in Scarborough have cost almost £3.5 million over five years 6 February 2020
• Bury Free Press: How empties like Cornhill Walk in Bury St Edmunds can impact West Suffolk Council's operation 13 February 2020
• Warrington Guardian: Business rates retention boost would come with ‘extra asks’ 19 February 2020

The story was also used by the BBC News Channel, Look North, South Today, East Midlands Today, BBC Radio Lincolnshire, BBC Radio Bristol, BBC Radio Nottingham, BBC Radio Scotland, BBC Sussex, Wales Today, BBC Tees, BBC Radio Shropshire, BBC Radio Cumbria, BBC Radio Devon, BBC Radio Ulster, BBC Radio Humberside.

• Bar chart: Percentage (%) of potential business rates income councils lost out on 2014-2018
• Bar chart: Lost business rates income from empty properties 2014-2018 (by government region)

• Empty premises relief data across Great Britain

• A full briefing pack on the story can be found here