Executive Summary

This research briefing was prepared in March 2026 using publicly available sources. It is intended for informational and journalistic purposes. It does not constitute legal advice. Recipients should seek independent legal advice regarding their specific compliance obligations.

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Key Findings

• The 2026 Strait of Hormuz crisis which was triggered by US-Israel military strikes on Iran on 28 February 2026, has effectively halted 20–25% of the world’s daily oil supply, with tanker traffic through the strait falling by over 90% within days of the conflict’s onset.
• Iran’s so-called “shadow fleet”, now estimated at 430+ tankers, with 87% already under US, UK, or EU sanctions, has become a major compliance challenge. This has been an ongoing challenge for the last few months as in December 2025, there were a total of over 180 vessels that had been designated by OFAC alone in a single 12-month period.
• Shipping law firms face a dual compliance obligation: they must conduct sanctions checks on their own clients AND on the vessels those clients own, operate, charter, or finance. With the UK’s strict-liability sanctions regime, even unintentional facilitation of a sanctioned vessel constitutes a criminal offence.
• Traditional KYC tooling built for individual and corporate client checks is structurally inadequate for vessel-level due diligence, which requires cross-referencing IMO numbers, beneficial ownership chains, and real-time sanctions list updates.
• Legl’s expansion of its client lifecycle management platform to include vessel sanctions screening directly addresses a critical gap in the legal technology market at the most timely possible moment.

Bottom Line

The convergence of an active conflict in one of the world’s most strategically vital waterways, an explosion in sanctioned vessel designations, and a regulatory environment that holds law firms strictly liable for sanctions breaches has created an acute compliance challenge for the shipping legal sector. Firms that cannot perform rapid, rigorous vessel sanctions checks risk regulatory challenges and possible reputational damage. The technology to solve this problem, purpose-built for the legal sector is being integrated into Legl’s client lifecycle management platform.

Recommended Action

Shipping law firms should urgently review their current vessel screening capabilities, assess the adequacy of their sanctions risk frameworks in light of the 2026 crisis, and engage with purpose-built legal technology platforms capable of automating vessel sanctions checks at the matter and transaction level.

Background & Context

The World’s Oil Jugular

The Strait of Hormuz is a narrow waterway separating Iran from Oman and the United Arab Emirates, connecting the Persian Gulf to the Gulf of Oman and, ultimately, the Indian Ocean. At its narrowest point, it is just 33 kilometres wide, with only two-mile-wide shipping lanes in each direction. Yet through this pinch-point passes approximately 20–25% of global oil supply and around 20% of total traded liquefied natural gas, which equates to roughly 21 million barrels of oil per day in 2024. No other single chokepoint in global maritime trade comes close to its strategic significance.

For decades, Western governments, shipping companies, and their legal advisers have gamed the scenario of a Hormuz closure. Since the Iran-Iraq war of the 1980s, the original “Tanker War”, through successive rounds of nuclear negotiations, proxy conflicts, and IRGC harassment of commercial vessels in the 2010s and early 2020s, the strait has remained open but perpetually threatened. In early 2026, the threat finally materialised.

The 2026 Crisis: How We Got Here

The immediate trigger was Operation Epic Fury, a coordinated US-Israeli airstrike campaign launched on 28 February 2026 targeting Iranian military facilities, nuclear infrastructure, and IRGC leadership, following the collapse of nuclear negotiations in Geneva and a prior 12-day air conflict in 2025. The death of Supreme Leader Ali Khamenei in the opening strikes fundamentally altered Iranian internal dynamics. Within hours, the IRGC issued formal warnings prohibiting commercial vessel passage through the strait. By 2 March 2026, Iran had officially declared the strait closed.

The retaliatory response was swift. Iran launched missiles and drones against US military bases in the Gulf, Israeli territory, and regional Gulf state infrastructure. By mid-March, Iran had made 21 confirmed attacks on merchant shipping. Tanker traffic dropped by 70% in the first days of the crisis and by over 90% within two weeks. Oil prices surged through $100 per barrel on 8 March 2026 for the first time in four years, ultimately peaking above $126 per barrel.

Simultaneously, Houthi forces in Yemen, reinvigorated by the resumption of Iranian backing, announced the resumption of attacks on commercial shipping in the Red Sea. The effect was a compound chokepoint crisis: both the Suez Canal route (via the Red Sea) and the Hormuz route were effectively off-limits simultaneously for the first time in history. Major carriers including Maersk, CMA CGM, and Hapag-Lloyd suspended transits indefinitely.

Why This Matters for Law Firms

Shipping is one of the most legally intensive commercial sectors in existence. Every large vessel requires a web of legal services: charter-party negotiations, P&I club representation, ship finance, cargo claims, insurance disputes, sale and purchase transactions, flag state registration, and, critically, sanctions compliance. The UK maritime legal market, centred on London’s historic position as the global hub for shipping arbitration and English law-governed contracts, serves a disproportionate share of global shipping clients.

When the sanctions landscape around shipping becomes as volatile as it has in 2025-26, the compliance burden on those law firms escalates dramatically. Sanctions lists change without warning. Vessels are renamed, re-flagged, and change ownership in hours. Shell company structures obscure beneficial ownership. And the UK’s sanctions regime, operating under the Sanctions and Anti-Money Laundering Act 2018, is strict liability: there is no “reasonable mistake” defence for a firm that unwittingly facilitates a sanctioned transaction.

Current State

The Hormuz Crisis as of March 2026

As of the week of 22 March 2026, the Strait of Hormuz remains in an active conflict zone. Only 16 AIS-visible vessel crossings were recorded in the previous seven-day period, against a normal baseline of well over 100 transits daily. Of those movements, the overwhelming majority are vessels linked to state actors, military supply chains, or the shadow fleet: the tankers and bulk carriers that have long operated outside conventional regulatory frameworks.

War-risk insurance premiums for Hormuz transits have risen from 0.125% to between 0.2% and 0.4% of ship insured value per transit, adding a quarter of a million dollars or more in insurance costs to a single VLCC (Very Large Crude Carrier) voyage. The P&I clubs that provide third-party liability cover for most of the world’s merchant fleet have begun formally excluding certain Iranian territorial waters from coverage.

The Sanctions Designation Explosion

The vessel sanctions landscape has been transformed over the past 18 months. Between January and December 2025, the US sanctioned more than 180 individual vessels transporting Iranian petroleum, a pace of designations without historical precedent. The total number of OFAC-sanctioned vessels registered with the International Maritime Organization increased by more than 46% in a single year, to over 1,800 named vessels. OFAC announced more than a dozen distinct rounds of maritime sanctions designations in 2025 alone.

The February 2026 US State Department action identified 14 additional shadow fleet vessels as blocked property for involvement in Iranian petroleum transport. By the outbreak of the current conflict, approximately 62% of vessels engaged in Iranian oil trade were falsely flagged, and 87% were already under US, UK, or EU sanctions. The Iranian shadow fleet operates at an estimated 430+ vessels, an order of magnitude larger than equivalent Russian or Venezuelan shadow fleets.

The Shadow Fleet and Its Evasion Tactics

Understanding what law firms are actually trying to screen against requires understanding how the shadow fleet operates. These vessels, typically ageing tankers flagged in jurisdictions with minimal oversight such as Gabon, Palau, or Cameroon, deploy a range of sophisticated evasion tactics that make simple name-based list screening almost worthless:

• AIS manipulation: vessels disable or ‘spoof’ their Automatic Identification System transponders, broadcasting false locations or simply going dark for days at a time to conceal ship-to-ship transfers or port calls in sanctioned jurisdictions.
• Vessel renaming and re-flagging: a sanctioned vessel may change its registered name and flag state within weeks of designation, with the IMO number (the vessel’s permanent identifier) being the only reliable constant.
• Shell company ownership chains: vessels are owned through multi-layered structures of SPVs, nominee directors, and trusts across multiple jurisdictions, deliberately obscuring the beneficial owner.
• Cargo laundering: Iranian crude is loaded at Kharg Island, transferred at sea in the Gulf of Oman or near Malaysia, and relabelled as Malaysian or Indonesian origin before delivery to Chinese buyers.
• False documentation: ship certificates, cargo manifests, and bill of lading paperwork are falsified at an industrial scale. In March 2026, Belgian special forces seized the tanker ETHERA near Ostend, operating under a fraudulent flag despite being listed under US, EU, and UK sanctions.

Compliance Impact

Law Firms Are Often the Last Line of Defence 

Shipping law firms are not passive bystanders to the sanctions regime, they are active participants in it, with direct legal obligations. Under the Sanctions and Anti-Money Laundering Act 2018, every UK legal professional is prohibited from dealing with designated persons or entities, including vessels. The SRA’s Code of Conduct requires firms to verify client identity (Rule 8.1) and to promptly alert OFSI where they have a ‘grounded suspicion’ that a counterparty is a sanctioned entity. The regime is strict liability: there is no defence of acting in good faith or in ignorance.

The practical consequence is that a shipping law firm advising a charterer that hires a vessel from an owner who turns out to be sanctioned may have committed a criminal offence, even if it never knew the vessel’s true ownership. This is not a theoretical risk. In 2024, a major shipping law firm publicly admitted to anti-money laundering failures, sending shockwaves through the maritime legal community. The case demonstrated that even firms with dedicated shipping practices and experienced compliance teams can fall short of regulatory expectations.

The SRA has been proactively writing to firms to assess their sanctions risk frameworks. Firms are being required not just to demonstrate that they have policies in place, but that those policies are operationally effective, ie that checks are actually being performed, documented, and updated as the lists change.

The Compliance Challenge Is Structurally Different for Vessels

The core difficulty for shipping law firms is that vessel-level due diligence is fundamentally different and more complex than standard client KYC. Most law firms have invested in AML and KYC tooling designed for checking individuals and corporates against sanctions lists: name matching, beneficial ownership resolution, PEP screening. These tools are inadequate for vessel sanctions work for several structural reasons:

• Vessels have multiple identifiers
• Ownership is deliberately opaque
• Lists change constantly and keeping pace manually is impractical

The Technology Gap Is Real and Acute

Until recently, vessel sanctions screening has been the preserve of specialist maritime data providers serving the financial institutions and commodity traders most directly exposed to maritime risk. These tools are powerful but expensive, complex, and designed for professional risk analysts, not for law firm fee earners who need to run a sanctions check before opening a new matter.

The legal sector has been poorly served by this landscape. Law firm compliance teams have typically relied on manual cross-referencing of the OFSI Consolidated List, the OFAC SDN List, and the UK Sanctions List, a time-consuming, error-prone process that does not scale in an environment where the lists are changing multiple times a month and the number of matters involving shipping counterparties may run into the hundreds per year.

The emergence of legal-sector-specific tools like Legl that integrate vessel sanctions screening into existing client lifecycle management and AML workflows represents a significant advance. Legl’s platform, which already serves over 600 law firms with KYC, AML, and sanctions screening, is now extending that capability to vessel-level checks, allowing fee earners to run vessel sanctions screening through the same interface they use for client onboarding and lifecycle management, with results that are documented, auditable, and updatable.

The Hormuz Crisis Has Accelerated a Pre-Existing Trend

It would be a mistake to frame the vessel sanctions challenge as solely a product of the 2026 crisis. The compliance landscape was already deteriorating dramatically through 2024-25, driven by: the Russia-Ukraine war and the resulting explosion in Russian shadow fleet activity; the Gaza conflict and Houthi attacks on Red Sea shipping; accelerating Iranian export volumes to China through obfuscated routes; and successive waves of regulatory expansion by OFAC, OFSI, and the EU. The Hormuz crisis has acted as an accelerant on a fire that was already burning.

The practical implication is that even if the current conflict de-escalates relatively quickly, the underlying compliance environment will remain dramatically more complex than it was in 2022. The 1,800+ OFAC-designated vessels are not going to be de-listed. The ownership evasion techniques are not going to be abandoned. The regulatory expectation of real-time, document-level sanctions checking is not going to diminish.

Implications

What This Means for Shipping Law Firms

The immediate implication of the current crisis is that any shipping law firm with active matters involving vessels, counterparties, or transactions connected to the Persian Gulf, Red Sea, or Iranian oil supply chains faces a heightened obligation to re-screen all relevant parties against current sanctions lists. The list of OFAC and OFSI-designated vessels has changed materially since the outbreak of hostilities. A vessel that was not sanctioned on 27 February 2026 may be sanctioned today.

The medium-term implication is structural: the shipping law firm that does not have systematic, auditable vessel screening capability embedded in its client lifecycle workflow will face increasing difficulty demonstrating adequate compliance to regulators, insurers, and institutional clients. The SRA is already asking questions. Professional indemnity insurers are already adjusting premiums for firms with inadequate AML frameworks. Major institutional clients, P&I clubs, shipping banks, commodity traders etc, are already asking their law firms to evidence their compliance processes.

Recommended Actions

For Shipping Law Firms: Immediate Priority Actions

The following actions are recommended in priority order, with suggested timelines:

1. Emergency Re-Screening of Active Matters 

All active matters involving vessels, shipowners, charterers, or transactions connected to Persian Gulf/Red Sea trade routes should be re-screened against current OFSI, OFAC, and EU sanctions lists - this can be achieved quickly using Legl’s client lifecycle management platform. The pace of new designations since 28 February 2026 means that matters opened even days before the crisis may now involve sanctioned parties. Where any match is identified, the firm must immediately suspend activity on the matter, seek legal advice, and consider whether an OFSI report is required.

2. Sanctions Risk Framework Review 

Firms should consider reviewing and updating their firm-wide risk assessments to reflect the material change in the shipping sanctions landscape since the crisis began. Updated assessments should specifically address: (a) the criteria for opening matters with shipping counterparties; (b) the point in the matter lifecycle at which vessel screening is required; (c) the specific lists and data sources used for vessel screening; and (d) the process for ongoing monitoring of sanctions status throughout a matter.

3. Technology Assessment 

Firms should assess whether their current KYC/AML tooling is capable of performing adequate vessel-level sanctions screening as part of a holistic framework for managing clients across their lifecycle with the firm. The assessment should specifically consider: whether the tool screens against all relevant lists (OFSI, OFAC, EU, UN); whether it can anchor screening to IMO numbers; whether it provides real-time or sufficiently frequent list updates; and whether results are logged in an auditable format. Where current tooling is inadequate, as is likely for firms using standard IDV and KYC point solutions, procurement of purpose-built vessel screening capability embedded in a client lifecycle management platform like Legl’s should be prioritised.

4. Staff Training 

Fee-earners in shipping practices should receive targeted training on the current sanctions environment, the specific indicators of shadow fleet involvement, and the firm’s procedures for escalating potential sanctions concerns.

5. Client Communication

Depending on the nature of the firm’s client relationships, proactive communication to shipping clients about enhanced sanctions checking procedures may be appropriate, both as a service to clients who have their own compliance obligations and as an evidencing measure demonstrating the firm’s regulatory diligence.

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This research briefing was prepared in March 2026 using publicly available sources. It is intended for informational and journalistic purposes. It does not constitute legal advice. Recipients should seek independent legal advice regarding their specific compliance obligations.

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