Cross Jurisdiction Regulatory Conflict Resolution

When to Use

Use this skill in multi-national quantitative trading firms whose orders are simultaneously in scope of more than one regime (e.g. US SEC/FINRA, EU MiFIR/MiFID II, UK FCA, Hong Kong SFC, Japan FSA). Where an entity in one jurisdiction routes to a venue in another, the two rulebooks can disagree — most sharply on Payment for Order Flow (PFOF), pre-trade client identification (LEI / national client ID), and short-selling constraints. This module is the pre-trade gate that resolves those three dimensions under Strictest Rule Primacy (obey the most restrictive applicable rule), blocks orders that cannot satisfy it, and emits an audit decision for every order it sees.

Scope caveat (important): Strictest Rule Primacy is a conservative firm policy heuristic, not a conflict-of-laws determination. It is valid only for prohibition-style rules, where complying with the strictest regime also complies with the others. It cannot resolve a mandate-vs-prohibition conflict — where regime A compels an act regime B forbids (blocking-statute situations, disclosure vs secrecy) — and the engine cannot detect such conflicts. Those require legal advice or a regulatory waiver.

When NOT to Use

• As a legal conflict-of-laws analysis. Irreconcilable mandate/prohibition conflicts are out of reach of a MAX/AND/OR resolver; escalate to counsel.
• As LEI issuance or GLEIF validation. is_valid_lei() is an offline ISO 17442 structural + checksum check. It cannot confirm the LEI is issued, belongs to the client, or is in an active registration status — all of which MiFIR Art. 26 reporting requires (ESMA validation rules require the code to exist in the GLEIF database with an entity status active on the trading date). A GLEIF lookup is still mandatory.
• As short-selling execution control. A PRICE_TEST result (Reg SHO Rule 201) is a constraint on the limit price relative to the national best bid, and a REPORTING result is a position-level disclosure duty. Neither can be evaluated from the order payload alone; this engine surfaces them as obligations for downstream systems. Locate/close-out requirements (Reg SHO Rule 203(b)) are not modelled at all.
• For rule dimensions it does not model. Research payment arrangements, best-execution policy, position limits, and market-abuse surveillance are out of scope. (Note that research unbundling is no longer a standing UK/EU conflict: the FCA permitted joint payments from 1 Aug 2024 in PS24/9, and the EU Listing Act, in force 4 Dec 2024, re-allowed joint payment for research and execution under MiFID II.)

Prerequisites

• Trade order payload: order_id, entity_jurisdiction, venue_jurisdiction, symbol, quantity, price, is_short, routed_via_pfof, lei_tag, and — for retail natural-person clients — is_natural_person_client / national_client_id.
• A JurisdictionRules profile per active jurisdiction, maintained by compliance: is_pfof_allowed, is_lei_mandatory, short_selling_restriction_level.
• Agreement on the severity ordering used for short selling (ShortSellingRestriction): NONE(0) < REPORTING(1) < PRICE_TEST(2) < BAN(3).

Workflow

1. Overlapping Jurisdiction Mapping:
   • Applicable set $\mathcal{J} = {\text{Entity Jurisdiction}, \text{Venue Jurisdiction}}$, codes trimmed and upper-cased, then sorted — audit strings must be byte-reproducible for two identical orders, which iterating a Python set does not guarantee.
   • A blank or non-string jurisdiction code raises ValueError; an order whose applicable regime is unknown must never reach an APPROVED decision.
2. Rule Matrix Resolution (Strictest Rule Primacy):
   • PFOF: allowed only if allowed in all of $\mathcal{J}$ (AND).
   • Client ID: LEI mandatory if mandatory in any of $\mathcal{J}$ (OR).
   • Short selling: MAX severity across $\mathcal{J}$, i.e. BAN > PRICE_TEST > REPORTING > NONE.
   • Decision point: an unregistered jurisdiction fails closed on every dimension (PFOF blocked, LEI mandatory, short selling banned) and is named in decision.unregistered_jurisdictions. An empty jurisdiction set raises ValueError rather than resolving to the most permissive rule set.
3. Pre-Trade Compliance Audit:
   • PFOF routing under a banning regime $\implies$ violation.
   • Client identification: for a legal entity, the LEI must pass ISO 17442 structural validation and its ISO/IEC 7064 MOD 97-10 check digits; for a natural person, an LEI is not the right identifier at all — a national client identifier (RTS 22 Art. 6 / Annex II, CONCAT fallback) is required instead.
   • Short selling: only BAN blocks the order. PRICE_TEST and REPORTING are returned in required_obligations for downstream enforcement — approving them silently would drop the obligation.
4. Audit Decision Generation:
   • Return RegulatoryComplianceDecision (status, resolved rule set, violations, obligations, unregistered jurisdictions, rationale) and append a defensive copy to engine.audit_trail, so a recorded REJECTED decision cannot be rewritten by a caller mutating the returned object.

Full procedure: see references/workflows.md. Standards reference: see references/standards.md. Printable pre-flight checklist: see assets/checklist.md.

Common Pitfalls

• Length-Only LEI Validation: len(lei) == 20 accepts AAAAAAAAAAAAAAAAAAAA and any typo'd or transposed code. ISO 17442 reserves positions 19-20 for ISO/IEC 7064 MOD 97-10 check digits — a well-formed LEI, read as one integer with A-Z mapped to 10-35, satisfies value % 97 == 1. An unchecked tag survives the gate and fails later at the NCA, after the trade.
• Demanding an LEI from a Natural Person: an LEI identifies a legal entity. A retail client is identified under MiFIR Art. 26 / RTS 22 by a national client identifier (or CONCAT), so a gate that requires a 20-character LEI universally rejects every legitimate retail order.
• Ranking a Disclosure Duty Above a Price Test: a net short position reporting obligation does not stop a trade; a Reg SHO Rule 201 price test does. Encoding reporting as the more severe level makes MAX resolution silently discard the price-test obligation when both regimes apply.
• Fail-Open on an Unconfigured Jurisdiction: an unknown jurisdiction code must resolve to the strictest value on every dimension. A fallback that is maximally strict for PFOF and LEI but only mid-severity for short selling permits shorts into a regime nobody has assessed.
• Non-Deterministic Audit Records: building the rationale string by joining an unordered set means the same order can produce different audit text on different runs — worthless for reconciliation and for demonstrating consistent treatment to a regulator.
• Applying Local Rules Only: a US entity routing to an EU venue is in scope of MiFIR Art. 39a (PFOF banned EU-wide since the last transitional exemption, Germany's, expired 30 June 2026) and MiFIR Art. 26 LEI reporting, regardless of the SEC's more permissive Rule 606 disclosure regime.
• Ignoring Entity Extraterritoriality: a UK subsidiary trading US equities is still subject to FCA conduct rules — including the FCA's long-standing treatment of PFOF as an inducement incompatible with COBS 2.3 and best execution (FSA FG12/13).
• Treating "Strictest" as a Legal Answer: strictest-rule primacy is a safe default for prohibitions only. It cannot arbitrate a rule that mandates what another jurisdiction forbids, and quietly returning APPROVED in that situation is worse than escalating.

Verification

• Instantiate CrossJurisdictionRegulatoryConflictEngine with US_SEC (PFOF allowed, LEI optional, PRICE_TEST) and EU_MIFID_II (PFOF banned, LEI mandatory, REPORTING). Submit a US-entity / EU-venue order with routed_via_pfof=True and no LEI: expect is_approved=False with exactly two violations (PFOF, LEI).
• Submit the same order with a structurally valid LEI and no PFOF: expect approval plus LEI_TAGGING_REQUIRED in required_obligations.
• Pass a 20-character string with wrong check digits (e.g. 5493001KJTIIGC8Y1S12, MOD 97 remainder 4): expect rejection. Transposing the first two characters of a valid LEI must also fail.
• Resolve {US_SEC, EU_MIFID_II} and verify the short level is PRICE_TEST, not REPORTING, and that a short order returns SHORT_SELL_PRICE_TEST_APPLIES.
• Submit an order with an unregistered venue jurisdiction: expect PFOF blocked, LEI mandatory, short selling banned, and the code listed in unregistered_jurisdictions. Call resolve_strictest_rules(set()) and expect ValueError.
• Submit a natural-person order with lei_tag=None and a national client ID: expect approval; remove the national ID and expect a CLIENT ID VIOLATION.
• Evaluate the same order with entity and venue jurisdictions swapped and verify applied_rules_summary is identical.
• Mutate a decision returned by engine.audit_trail and verify the engine's own record is unchanged.
• Run python -m unittest discover -s skills/cross-jurisdiction-regulatory-conflict-resolution/scripts.

Related Skills

• cross-border-data-transfer-restrictions-for-trade-data
• best-execution-record-keeping-global
• us-reg-sho-short-sale-locate-requirements
• eu-short-selling-regulation-disclosure-thresholds