March 16: The day a £2.99 billion law firm discovered irony has teeth

McDermott Will & Schulte's London office managed to miss its own Companies House identity verification deadline while advising clients on regulatory compliance. Thirty-one of the firm's 38 UK LLP members remain listed as "unverified" on the public register after their confirmation statement was rejected on March 16, 2026.

The deadline for the firm's partners to prove they were genuine human beings rather than corporate phantoms was March 16. But despite filing their annual confirmation statement on Friday the 13th—"ahead of the deadline," a spokesperson insisted with touching optimism—Companies House returned it three days later due to "a mismatch between one of the partner's names as it appeared on the Confirmation Statement compared to how their name appeared in the ID verification process."

One suspects the partner in question will be getting some particularly pointed feedback during their next performance review.

What this means for your Monday morning

The McDermott debacle illustrates why leaving identity verification to the last minute remains spectacularly unwise. Under the Economic Crime and Corporate Transparency Act 2023, directors and people with significant control must verify their identities with Companies House—a requirement that became mandatory from November 18, 2025.

More pressingly, you have nine days before an even bigger compliance cliff edge arrives.

The March 31 massacre approaches

On March 31, 2026, HMRC and Companies House will permanently close their free joint filing service, known as the CATO portal. After that date, companies must use commercial software to file Corporation Tax returns, with costs typically ranging from £80 to £150 annually.

This affects every business currently using the free service to file CT600 forms and company accounts simultaneously. No exemptions. No extensions. No free alternative.

Your essential pre-closure checklist:

• Download at least three years of previously filed returns from the CATO portal before March 31
• Select HMRC-approved commercial software for future CT600 filings
• Decide whether to continue using Companies House WebFiling (free until 2027) or move to integrated software
• Test your chosen software with dummy data rather than discovering its limitations at 11:55 PM on filing day

Companies House emphasizes that after March 31, "you won't be able to access historic returns through" the portal. Once it's gone, it's gone.

The identity verification endgame

Meanwhile, existing directors have until November 17, 2026, to complete identity verification. But here's the trap: Companies House cannot process your confirmation statement if any director remains unverified.

The system rejects the filing entirely. Your company then faces automatic late filing penalties starting at £150, rising to £1,500 for delays exceeding six months. Directors who fail to verify face criminal prosecution under the Economic Crime and Corporate Transparency Act.

For People with Significant Control who aren't directors, verification deadlines follow birth months. If Companies House records show you were born in March 1980, your 14-day verification window opened on March 1, 2026.

The workflow reality

The McDermott incident reveals how narrow the margin for error has become. Even a single character mismatch between verification records and filing documents triggers rejection.

Filing on Friday the 13th for a Monday deadline left zero buffer for corrections. In contrast, firms completing verification months in advance can resolve discrepancies without panic or public embarrassment.

Smarter practices now front-load compliance tasks. Complete identity verification immediately. Download CATO records this week. Select and test commercial software before you need it urgently.

Next deadline on the horizon

Confirmation statements continue annually, but the stakes have shifted. Each filing now requires verified identity codes for all directors and PSCs. One missing verification blocks the entire submission.

Companies incorporated in March will face their first post-CATO confirmation statements in March 2027—by which point both the free filing service and the identity verification grace period will be historical footnotes.

The firms adapting now will find March 2027 unremarkable. Those following McDermott's last-minute approach may discover that professional embarrassment scales with firm size.