Master data
Master data is the core, shared data about the key entities a business deals with: clients, counterparties, products, accounts, legal entities and employees. It changes less often than transactions and is reused by many processes. Master data management (MDM) keeps one trusted version of it.
Roles that need it
What it is
Master data describes the things a business transacts with or about. In a bank, the main domains are client and counterparty data (names, legal identifiers, addresses, risk ratings), product and instrument data, account data, and internal data such as legal entities, cost centres and the chart of accounts.
Master data sits between two other kinds of data. Reference data is the set of codes used to classify it, such as country or currency codes. Transaction data records events, such as a payment or a trade, and points to master data records. Master data management (MDM) is the discipline and the tooling that creates, matches, merges and distributes one trusted record per entity, often called the golden record.
Why it matters
Errors in master data spread to every process that reuses it. A duplicated client can lead to a credit limit counted twice, a missed sanctions match or two different risk ratings for the same company. Supervisors expect banks to identify counterparties consistently across the group, which is why the legal entity identifier (LEI) is widely used as a matching key. Clean master data also cuts manual work in onboarding, reporting and reconciliations.
Worked example
Illustrative numbers. A bank holds 50,000 corporate client records across three systems. A matching exercise using the LEI, registered name and address finds 4,000 likely duplicates, so 46,000 distinct clients remain. Stewards review 500 uncertain matches by hand. After the merge, the bank finds that 120 clients had exposures in two systems that were never added together. Their combined exposure is 15 percent higher than the largest single record showed, which changes the limit check for 9 of them.
Who uses it
Master data specialists run the MDM platform, set matching rules and fix records. Reference and security master data analysts maintain instrument and issuer data in investment firms. Data governance analysts set ownership and quality standards for each domain. Corporate onboarding (KYC) analysts create and update client records and are often the first line of quality. General accountants rely on master data for the chart of accounts, cost centres and vendor records. Data analysts in banking depend on it to join datasets correctly.
Common confusions
Master data and reference data are often used as synonyms. Reference data is a list of permitted values (for example ISO country codes); master data is the record of a real entity that uses those values. Another confusion is to see MDM as only a technology project. Without data owners, stewards and agreed definitions, a new tool just stores the same duplicates faster. Finally, the golden record is a logical concept: it may live in one hub or be assembled from several sources under agreed survivorship rules.