How to Structure Matter Numbering and Naming Conventions

Sep 21

12 min read

Every law firm eventually discovers that the way it numbers and names its matters is a decision with consequences far beyond tidiness. A matter number appears on engagement letters, invoices, trust ledger entries, file labels, document footers, emails and court bundles. It is the key by which time is recorded, disbursements are allocated, documents are retrieved and files are retained and destroyed. A well-designed matter numbering system makes all of these tasks routine. A poorly designed one produces duplicate numbers, mis-posted time, untraceable files and, in the worst cases, conflicts of interest that are not detected because the firm cannot reliably search its own records.

Many firms inherit their conventions rather than choose them. A numbering scheme begins as a simple sequence on a spreadsheet, is extended by a succession of administrators, and ends up as a patchwork of formats, with one set of numbers for litigation, another for conveyancing, and a number of matters whose names mean something only to the fee earner who opened them. Changing a system in use is possible but costly, which is why it is worth designing deliberately at the outset, or at least before the firm grows further.

This article sets out the principles of good matter numbering and naming, compares the main structural options, identifies what should and should not be encoded in a number, and describes how to implement and maintain a convention. It is written for practitioners in small and mid-sized firms and does not assume any particular software, though the final section considers how a practice management system can enforce the convention.

What a matter number is for

It is worth stating the functions of a matter number precisely, because a design that serves one function badly will cause problems in the others.

Unique identification. The number must identify exactly one matter, now and permanently. No two matters, whether open or closed, should ever share a number.
Linkage. It connects time entries, disbursements, invoices, trust or client account transactions, documents, emails and correspondence to a single matter.
Retrieval. A person holding only the number should be able to find the matter and its file, whether digital or physical, without ambiguity.
Communication. The number is quoted by clients, counsel, courts and third parties on correspondence. It should be short enough to quote and robust enough to survive being read over the telephone.
Reporting. Where the number encodes useful attributes, such as year of opening or practice area, it allows simple analysis without extra data.
Retention and destruction. The firm must be able to identify when a matter closed, when its retention period expires and where the file is held.

Distinguishing the client number, the matter number and the matter name

Three identifiers are often confused, and keeping them distinct is the foundation of a clean design.

The client number

The client is the person or entity for whom the firm acts. A client may have many matters over many years. Many firms therefore use a two-part reference, a client number followed by a matter number, so that all work for a client can be listed together and so that conflict checking and client due diligence records are attached to the client once and not repeated for each matter.

The matter number

The matter number identifies the particular engagement within that client relationship. It should be generated, not invented, and should never be reused. Where the firm prefers a single number for the matter, the client component can be embedded in it or held as a separate field.

The matter name

The matter name is a human-readable description. It supports quick recognition in a list but is not an identifier. Names are not unique, they are altered over time and they are the cause of most retrieval confusion. A convention for names is useful, but a name must never be used where a number is required.

Structural options for a matter numbering system

Several structures are in common use. Each has advantages and drawbacks, and the right choice depends on the size of the firm, the variety of its work and the capabilities of the system in which the numbers will be held.

Structure	Description	Advantages	Drawbacks
Simple sequential	A single running number assigned in order of opening	Easy to generate, impossible to duplicate, no encoded data to become wrong	Carries no information; client grouping must be handled by other fields
Year and sequence	The year of opening followed by a running number that restarts each year	Shows age at a glance, helps with retention and archiving, keeps numbers short	Year can mislead if a matter is reopened; sequence restart requires care to avoid duplicates across years
Client and matter	A client number followed by a matter number that runs within the client	Groups all work for a client, supports client-level conflict and due diligence records, mirrors common practice	Longer to quote; requires a reliable client register
Practice area prefix	A short code for the area of law followed by a sequence	Allows reporting by area directly from the number	Matters change character; area code may become inaccurate; prefix proliferation
Fee earner prefix	The initials of the responsible attorney followed by a sequence	Easy for the individual to recognise	Breaks on handover or departure; initials may collide; discouraged for most firms
Hybrid	A combination, such as client number, year and sequence	Captures several useful attributes	Greatest complexity; highest risk of error if entered manually

For most small and mid-sized firms, the client and matter structure, with the matter component running sequentially within each client, offers the best balance. It supports the grouping that fee earners and accounts staff need, and it keeps the conflict and client due diligence record at the right level. A year component may be added where retention planning is helped by it.

What to encode in the number and what to leave out

The temptation in designing a numbering system is to encode as much information as possible. This is usually a mistake, for a simple reason: any attribute encoded in a number is fixed when the number is created, but the real-world attribute may change.

Attributes that are safe to encode

Client identity. A client does not generally change identity within a matter, and a client number is a stable reference.
Year of opening. The year in which the matter was opened is a historical fact and does not change.
A running sequence. It provides uniqueness.

Attributes that are risky to encode

Practice area. A matter that begins as an employment dispute may become a commercial claim. If the number says employment, every report derived from it will be wrong. Hold the area as a data field that can be corrected.
Responsible attorney. Responsibility changes. A number that encodes a departed attorney's initials is a continuing source of confusion.
Office or location. Firms reorganise. Hold location as a field.
Billing arrangement. Fee arrangements may be renegotiated. Hold as a field.
Status. Open, closed or on hold is a status and should never appear in the identifier.

The governing principle is that an identifier should identify and nothing else. Attributes that change belong in fields that can be updated and reported on. Where a firm insists on an encoded practice area, it should accept that the code reflects the area at opening and should not rely on it for management reporting.

Design rules for the number itself

Unique and never reused. Numbers of closed, withdrawn or mistakenly opened matters are retired, not recycled. A matter opened in error should be marked void, not deleted, so that the sequence has no unexplained gaps.
Fixed format. Use a consistent length with leading zeros where needed, so that numbers sort correctly. A sequence that reaches the next order of magnitude otherwise sorts out of order in lists.
Machine generated. Where possible the system generates the number. Manual allocation from a spreadsheet invites duplicates, particularly where two people open matters at the same time.
Readable aloud. Avoid characters that are easily confused, such as the letter O and the digit zero, or the letter I and the digit one. Keep separators consistent, and use a single separator character throughout.
Short enough to quote. A reference that runs to many characters will be abbreviated or mis-copied by clients and third parties.
Sortable. A number should sort in a meaningful order in a file listing, which generally means placing the stable elements first.
Permanent. A matter keeps its number for life, including on reopening. If a matter is reopened after closure, the same number is used and a note records the reopening.

Conventions for matter names

A matter name should allow any member of the firm to recognise a matter in a list, and should give a stranger enough context to understand it without revealing anything that should not be visible. A convention helps because the same type of information then appears in the same place every time.

A suggested naming pattern

One workable pattern is the client name, followed by a short descriptor of the subject, followed where useful by the counterparty. For example, a matter might be named with the client's surname, a short phrase describing a purchase of premises, and the address or the name of the other side. The pattern should be written down and applied by everyone.

Rules for names

Use the client's full, correct legal name in the client record and a consistent short form in the matter name. Do not mix abbreviations, nicknames and trading names.
Place the most discriminating information first, so that names are distinguishable in a truncated list.
Avoid information that is sensitive or prejudicial in a title. Matter names often appear on shared screens, in calendar invitations and in email subject lines. The subject of the retainer should be stated in neutral terms.
Avoid punctuation and characters that cause problems in file systems and in some software, such as slashes, colons and quotation marks.
Avoid the use of dates in names unless a date is part of the identity of the matter, since dates multiply and age.
Keep names short enough to display fully. A name that is truncated at the point of greatest interest is of little use.

Names of individuals and organisations

Spell and order names consistently. A decision between family name first and given name first should be made once and applied throughout. Where a client has multiple names, the firm should record the legal name in the client register and use the same form in the matter name, while holding known aliases as separate searchable data. Consistent entry matters because conflict checks depend on searching names, and a search for one spelling will miss another.

Linking the convention to conflict checks and client due diligence

The numbering convention is not only an administrative device; it supports regulatory obligations. A conflict check is a search of the firm's records for existing and former clients and for other parties to matters, and its reliability depends on the quality of the data against which it is run.

A firm should therefore record, for every matter, not only the client but also the opposing parties, related parties and any other person whose involvement is relevant to conflict assessment. These should be held in structured fields associated with the matter number, not buried in a free-text name or in a document. The conflict check should be logged against the matter, with the date, the person who performed it and the result.

The rules on conflicts, on client identification and verification, and on anti-money laundering obligations differ by jurisdiction and by the nature of the work, and the firm should take its requirements from its own regulator. What is common is that the firm needs to be able to demonstrate, for each matter, what checks were carried out and when. A numbering system that links each matter to its client record and to those checks supports that demonstration.

Handling special cases

Related matters

Some matters arise from others, such as an appeal following a trial, an enforcement action following a judgment, or a series of transactions for the same client in a single project. The firm must decide whether a related matter receives a new number or is a sub-matter of the first. A practical rule is that a new engagement, which has its own scope, retainer and billing, receives a new number, and that the relationship is recorded in a field. Sub-matter numbering may be justified where one client requires a single invoice or budget across several workstreams.

Retainers and general advice

Ongoing relationships where the client asks occasional questions are best handled under a general matter opened for the purpose, with time recorded to it, instead of by opening a new matter for each telephone call. The scope of the general retainer should be recorded in the engagement letter, and the firm should review whether a discrete task has outgrown it and requires its own matter.

Internal and non-chargeable matters

Time spent on firm administration, training, business development and unbilled work should be recorded against internal matter numbers, so that all time has a destination. A separate range or prefix, documented in the convention, distinguishes these from client matters and keeps them out of client reports.

Mergers, acquisitions of practices and migrations

When firms combine, or when a firm migrates to a new system, existing numbers must be preserved or mapped. The firm should retain the legacy number as a searchable field against the new number, since documents, correspondence and court records will continue to refer to the old reference for years.

Matters opened in error and duplicates

Duplicate matters for the same engagement are a common consequence of weak intake. The firm should provide a process for merging or voiding, which records the reason and preserves the history. Deletion destroys the audit trail and should be avoided.

Extending the convention to documents and folders

A matter number is most useful when it appears consistently wherever the matter's material is stored. Where documents are held in a document management system attached to the matter, the association is made by the system. Where documents are held in folder structures, the top-level folder should bear the matter number and name, and the internal structure should follow a standard template, such as correspondence, pleadings, evidence, drafts and billing.

File names should be consistent as well. A common pattern is the date in a sortable form, a short description and a version indicator. Names such as final, final2 and latest are unhelpful; a version number and the date allow the current version to be identified without opening the document. Email subject lines carrying the matter number allow correspondence to be filed and retrieved reliably, and the firm may adopt a rule that the matter number appears at the start of any subject line.

Physical files, where they are still kept, should carry the matter number prominently on the cover and spine, with a location reference recorded in the system.

Implementing a new convention or correcting an existing one

Changing a convention in a firm that is already operating requires care. The following sequence reduces disruption.

Audit the current position. Export the list of existing matters and examine the formats in use, the duplicates, the gaps and the matters with no client reference.
Agree the design. Settle the structure, the fixed format, the naming rules and the fields, and record them in a short written standard that is approved by the principals.
Decide the cut-over rule. A common and safe approach is to apply the new convention to all matters opened after a fixed date and to leave existing matters under their old numbers, with a legacy field for cross-reference. Renumbering live matters is rarely worth the risk, except where the old numbers are unreliable.
Clean the client register. Correct duplicate or inconsistent client records before they are linked to the new numbers.
Train and communicate. Everyone who opens matters, including secretaries and accounts staff, should be trained, with a one-page reference to hand.
Assign ownership. One person, often the practice manager, is responsible for opening matters or for approving them, so that the standard is applied consistently.
Audit compliance. After the first few months, sample new matters against the standard and correct deviations.

Governance and maintenance

A convention degrades without maintenance. The firm should treat the standard as a controlled document, with an owner, a version and a review date. Changes to the structure, the naming rules or the list of codes should be made deliberately and recorded. A short list of approved codes, for example for practice areas used in reporting, should be maintained centrally and not extended by individual fee earners.

The matter opening process should be a defined sequence: receive instructions, run the conflict and client identification checks, create the client record if required, open the matter and generate the number, send the engagement letter quoting the number, and confirm to the fee earner and accounts. No time should be recorded and no funds received against a matter until it has been properly opened. Applying this discipline prevents the common failure of unnumbered work that is later allocated retrospectively.

Practical next steps

Export the firm's current matter list and identify duplicates, gaps, inconsistent formats and matters without a client reference.
Decide whether the firm will use a simple sequence, a year and sequence, or a client and matter structure, and document the choice and the reasons.
Write the numbering standard, including the fixed format, the rule that numbers are never reused, and the treatment of void and reopened matters.
Write the naming standard, including the order of elements, treatment of names and rules on sensitive information.
Define the structured fields that must be completed at opening, including the opposing parties, the responsible attorney, the practice area and the conflict check record.
Fix a cut-over date, and preserve legacy numbers in a searchable field.
Appoint an owner for matter opening and for periodic audit of the standard.
Apply the same matter number to folders, document names, email subject lines and physical files.

How practice management software supports the convention

A practice management platform can generate numbers automatically, prevent duplicates, require the completion of conflict and client fields before a matter is opened, and carry the matter number through time entries, invoices, documents and correspondence. Legalytech provides matter and client records within a single system for these purposes, which allows the firm's numbering standard to be enforced by the software rather than relying on manual care alone.

This article is provided for general information only and does not constitute legal advice. Practitioners should consult the rules of their own jurisdiction and regulator.