Why do banks require an LEI number?

3 min read Updated July 2026
A modern bank building — banks use LEI numbers to identify legal-entity clients in reportable transactions

When a legal entity carries out a reportable financial transaction, the bank or investment firm must identify the client in its transaction report. The LEI number provides that standard identifier.

The FCA states that a firm subject to UK MiFIR transaction reporting cannot execute a trade for a client that is eligible for an LEI but does not have one. This is why a bank or broker may ask for the number before accepting an order.

When does a bank ask for an LEI number?

An LEI number may be required when a company or other legal structure carries out a reportable transaction in financial instruments, including:

  • shares and bonds;
  • exchange-traded funds;
  • options, futures, forwards and swaps;
  • other instruments covered by UK MiFIR or UK EMIR reporting rules.

A bank may request the LEI number when an investment account or service is opened so that a later transaction is not delayed.

Why can’t the bank trade without it?

Banks and investment firms must report certain transactions to the relevant authority. Where the client is a legal entity or legal structure, the report uses the LEI number to identify that client consistently.

Under the UK MiFIR rules described by the FCA, the firm must have the client’s LEI before executing a transaction that creates a reporting obligation. The requirement can apply to companies, charities, trusts and other structures that are eligible for an LEI.

The LEI number also lets the bank match the client with the correct public GLEIF record, even where organisations in different countries have similar names.

Does every company need an LEI number?

No. Incorporating a company or opening an ordinary business bank account does not by itself create a general LEI requirement. An LEI number is not normally needed for routine payments.

The need usually arises when the organisation trades in a financial instrument or has another reporting obligation that requires a standard legal-entity identifier. The bank, broker or investment provider should confirm the rule for the specific transaction.

What should you do if a bank asks for one?

First, check whether the organisation already has an LEI number.

  • If an LEI number exists, provide it to the bank and confirm whether its current status is acceptable for the transaction.
  • If the organisation does not have one, apply for an LEI number before the trade.
  • If the LEI status is lapsed and an active record is required, renew the existing LEI number. Do not apply for a second number.

The FCA’s current guidance distinguishes between different reporting roles and transaction types, particularly under UK EMIR. The bank or reporting firm remains the right party to confirm whether renewal is required for a particular transaction.

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