In July 2020 we reported on the rate of insolvencies and the changing status of companies during the coronavirus pandemic. The analysis suggests there may be many companies now operating as so-called "zombie companies": businesses that function day-to-day, but cannot pay off the full debt they owe or find cash to invest and grow.

The BBC Shared Data Unit looked at how many companies had posted insolvency notices in the London Gazette, the official paper of record for public notices. A company is insolvent when it can't pay its debts.

Our investigation found there was a spike of 4,200 insolvencies in March as the UK headed into lockdown.

You can find the briefing pack here with more on the methodology

• Google Sheet: data on insolvencies and new businesses by local authority and type/sector

• Julie Palmer, partner, financial consultants Begbies Traynor
• Stuart Adam, Institute for Fiscal Studies (IFS)
• Richard Millward, business owner
• Ric Traynor, executive chairman, Begbies Traynor
• Shahid Hussain, founder of new food delivery business, Essex
• Tom Parkinson, nurse who is hoping to register his baking business
• Spokesman, Government

• Multiple line chart: insolvencies during the first six months of 2019 vs 2020
• Column chart: new companies by incorporation date, January to June 2020

• Python notebook: Scraping the Gazette for insolvency notices (sequential): Python script for scraping notices from the London Gazette
• R script for collating Gazette data and joining to Companies House for analysis

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:

• Bournemouth Echo: Number of company insolvencies in Bournemouth area revealed 4 August 2020
• Business Live: State bail-outs keeping firms on life-support – but warnings more will soon start going under 28 July 2020
• Cornish Times: Businesses in 'hibernation' could face greater challenges emerging from lockdown 28 July 2020
• Eagle Radio: More businesses go under in Surrey and Hampshire during coronavirus lockdown 29 July 2020
• Get Surrey: Number of Surrey businesses going bust doubled in lockdown 29 July 2020
• Harrow Times: Rise in number of Watford companies going bust during lockdown 3 August 2020
• Herefordshire Mercury: The number of companies going bust nearly doubles in Hertfordshire during lockdown 28 July 2020
• Hunts Post: More than 300 new businesses set up in Huntingdonshire during lockdown 30 July 2020
• Irish News: Northern Ireland 'may be facing an insolvency tsunami when courts reopen' 28 July 2020
• Kidderminster Shuttle 232 new businesses registered in Worcester during lockdown 27 July 2020
• Lancashire and Morecambe Citizen: East Lancashire insolvencies: Data reveals coronavirus impact 29 July 2020
• Lancashire Telegraph: East Lancashire insolvencies: Data reveals coronavirus impact 29 July 2020
• Leeds Live: Drop in Leeds businesses going bankrupt despite coronavirus lockdown 27 July 2020
• Nantwich News: 37 Cheshire East businesses file insolvency notices in first 3 months of lockdown 27 July 2020
• Northampton Chronicle and Echo: Fears over Northampton businesses going insolvent after being kept afloat by government during coronavirus lockdown 29 July 2020
• Portsmouth News: Surge in Portsmouth firms filing for insolvency during lockdown research finds 5 August 2020
• Peterborough Matters: How lockdown has impacted firms in Peterborough 26 July 2020
• SpiritFM: More businesses go under in West Sussex during coronavirus lockdown 29 July 2020
• The Scotland Herald: Experts warn coronavirus crisis is creating 'zombie' firms 29 July 2020
• Worcester News: 232 new businesses registered in Worcester during lockdown 27 July 2020
• Wigan Today: Hundreds of new Wigan businesses launched amid Covid-19 challenges 7 August 2020
• Yorkshire Live: The incredible stats that show the true economic impact of Covid-19 on Kirklees business so far 28 July 2020
• Birmingham Live: Thousands of Birmingham businesses in financial distress - how to keep your company safe 19 November 2020
• Manchester Evening News: Thousands of Manchester businesses in financial distress - this free advice can help 3 December 2020

You can find all coronavirus-related stories by the BBC data units tagged 'coronavirus' here