Companies House Data / Accounts Filing
How Many Companies File in XBRL vs Paper?
96% of UK company accounts were filed in XBRL format in May 2026, up from 91% in January 2025, as businesses continue moving away from paper filing ahead of Companies House's mandatory digital filing deadline of 1 April 2028.
Summary
The proportion of company accounts filed digitally in XBRL format has risen steadily over the past 17 months, from 91% in January 2025 to 96% in May 2026. Paper filing, while shrinking as a share of the total, has not disappeared, with between 12,000 and 37,000 accounts still filed on paper each month across the period.
December 2025 was by far the busiest filing month, with 507,000 accounts filed in total (477,000 XBRL and 30,000 paper). This reflects the concentration of statutory filing deadlines around the turn of the calendar year, when a large cohort of companies with March year ends reach their nine month filing deadline.
The lowest XBRL share in the dataset was recorded in September 2025, at 90%, when paper filings rose to 37,000, the highest paper volume of any month covered. Since then, the XBRL share has recovered and pushed to new highs, reaching 96% in both March and May 2026.
Key Insights
- XBRL share has grown from 91% to 96% in the 17 months to May 2026.
- Average monthly XBRL share was 93.3% across 2025, rising to 94.8% across the first five months of 2026.
- December is consistently the peak filing month, driven by year end deadline clustering rather than a shift in filing method.
- Paper filing has not gone away, with a spike to 37,000 paper filings in September 2025 showing the shift is not fully linear.
- The lowest paper volumes on record (12,000 to 13,000 a month) have all occurred in 2026, suggesting the run-up to the 2028 mandate is already accelerating adoption.
Filing Type by Month
Companies House accounts filings by type, January 2025 to May 2026| Month | XBRL # | Paper # | XBRL % | Paper % |
|---|---|---|---|---|
| May-26 | 277,000 | 13,000 | 96% | 4% |
| Apr-26 | 275,000 | 17,000 | 94% | 6% |
| Mar-26 | 302,000 | 12,000 | 96% | 4% |
| Feb-26 | 258,000 | 13,000 | 95% | 5% |
| Jan-26 | 310,000 | 25,000 | 93% | 7% |
| Dec-25 | 477,000 | 30,000 | 94% | 6% |
| Nov-25 | 309,000 | 17,000 | 95% | 5% |
| Oct-25 | 282,000 | 27,000 | 91% | 9% |
| Sep-25 | 332,000 | 37,000 | 90% | 10% |
| Aug-25 | 276,000 | 21,000 | 93% | 7% |
| Jul-25 | 318,000 | 25,000 | 93% | 7% |
| Jun-25 | 253,000 | 20,000 | 93% | 7% |
| May-25 | 301,000 | 15,000 | 95% | 5% |
| Apr-25 | 281,000 | 19,000 | 94% | 6% |
| Mar-25 | 289,000 | 14,000 | 95% | 5% |
| Feb-25 | 246,000 | 12,000 | 95% | 5% |
| Jan-25 | 253,000 | 26,000 | 91% | 9% |
What This Means
With mandatory digital filing due to take effect from 1 April 2028, the businesses and advisers still relying on paper accounts have a shrinking window to transition. The data suggests the shift is well underway but uneven, with month-to-month volatility in paper filing volumes rather than a smooth decline. Accountants and company secretarial teams supporting clients who still file on paper should treat the next two years as a transition period rather than leave the switch to the deadline itself.
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