Types of Filing Systems and Their Advantages.

Most people asking what type of filing system they need are really asking two questions at once. The first is how the files should be ordered. The second is what they should be kept in. They are separate decisions, they are taken in that order, and getting them the wrong way round is why so many filing systems end up being rebuilt within a few years.

This piece covers both: the four classifications that determine how a file is found, and the physical formats that follow from them.

The four main types: how files are ordered

Almost every filing system in use is one of four classifications, or a deliberate combination of them. The right one is decided by how people will look a file up, not by how the files arrive.

Alphabetical

Files are ordered by name — of a person, a company, or a subject. It is the default for a reason: no index is needed, anyone can use it without training, and a misfiled document is usually found quickly because it will be close to where it should be.

It breaks down at scale and at the edges. Common surnames collide, organisations rename themselves, and nobody agrees whether a company beginning “The” files under T. Past a few thousand files, the exceptions need a written rule or the system drifts.

Numerical

Each file is given a number and filed in sequence, with a separate index linking names to numbers. It takes more to set up and it cannot be used without the index, which has to be maintained.

What it buys is capacity and confidentiality. Numbers never collide, the sequence extends indefinitely without reorganisation, and a file on a desk gives nothing away to someone walking past. That combination is why patient records, case files and personnel records are so often numerical.

Chronological

Files are ordered by date. This suits material where the date is genuinely how people search — invoices, meeting minutes, correspondence logs, anything reviewed or destroyed on a timetable.

Its weakness is obvious: if you do not know roughly when something happened, you cannot find it. It works best as a second level inside another classification rather than as the whole system.

Subject or category

Files are grouped by what they are about — by department, project, contract type or function. It matches how people think about their work, which makes it comfortable to use, and it keeps related material together.

It is also the most fragile. Subject headings are a matter of judgement, and two people will file the same document in two different places unless the categories are written down and kept to. A subject system without a maintained list of headings degrades faster than any other kind.

Two variants come up often enough to mention. Geographical filing orders by region or site, and is really subject filing with location as the category. Alphanumeric combines a letter code with a number, which gives the readability of alphabetical with the capacity of numerical, at the cost of a slightly more complicated rule.

Rackline’s post on the two main methods of filing looks at the underlying distinction between direct and indirect access in more detail.

Format: what the classification then needs

Once the ordering is settled, the format follows from it. The question is no longer how files are arranged but how they are held, and that depends on how often they are reached for.

Vertical cabinets hold files front to back in deep drawers. They suit smaller, self-contained sets and offices where the cabinet has to sit against a wall in a narrow footprint. Lateral cabinets hold files side to side across a wider drawer, so a whole row is visible at once and retrieval is faster. The comparison between vertical and lateral cabinets works through which suits which situation.

Suspension filing — pockets hanging from rails — is what most offices mean by a filing system. It keeps documents upright and undamaged, and files can be lifted out and replaced without disturbing their neighbours. Hung laterally in open shelving rather than in drawers, the same principle gives considerably more capacity in the same floor area, because no space is given over to drawer travel.

Box files and archive boxes are for material that has stopped being consulted regularly. They are cheap, they stack, and they are the right answer for anything approaching the end of its retention period rather than the start.

Density: when the filing outgrows the room

Most filing problems presented as “we need a better system” are really capacity problems. The classification is fine and the format is fine; there is simply more paper than floor area.

At that point the decision moves from cabinets to shelving. Open lateral shelving removes drawer travel. Mobile shelving goes further by mounting the bays on carriages so that only one aisle is open at a time, turning the space the other aisles occupied into storage. For a filing room that is full but cannot grow, that is usually the only answer that does not involve renting more floor.

The trade-off is access. One open aisle serves one person at a time, so a file room in continuous use by a team may be better split — current files on static shelving, closed files on mobile. Rackline’s Fileline range is built around that lateral filing principle.

Retention: the part most systems leave out

A filing system without a disposal rule only ever grows. Every classification above assumes files leave at some point, and most offices have never written down when.

The practical step is to agree a retention period for each category of file, record it, and apply it on a fixed date each year. Legal and regulatory minimums set the floor; beyond that it is an organisational decision. Doing this before buying storage frequently reduces the requirement enough to change what needs buying — it is worth doing first, not last.

Choosing between them: the questions that settle it

Five questions will usually decide the whole specification:

• How will people look a file up — by name, by number, by date, or by topic? That names the classification.
• How many files are there now, measured in linear metres rather than counted?
• How much does the collection grow in a year, taken from actual intake rather than an estimate?
• How often is a file retrieved, by how many people, and at the same time?
• Does anything need to be out of sight of people passing the desk?

The first and last questions decide the classification. The middle three decide the format and whether static or mobile shelving is appropriate. Rackline’s piece on why filing and shelving matter to an organisation covers the operational case, and setting up filing in an office deals with the practicalities of a smaller installation.

So which type of filing system do you need?

For most offices the honest answer is alphabetical for anything staff look up by name, numerical for anything confidential or high-volume, and a written rule covering the exceptions in both. The format then follows the capacity: cabinets while the volume is modest, lateral shelving when it is not, and mobile shelving when the room has run out before the filing has.

What matters more than the choice is writing it down. A filing system fails when the rule exists only in the head of whoever set it up, and that is true whichever of the four classifications it uses.

Rackline has designed, manufactured and installed filing and storage systems in the UK since 1984, for offices, hospitals, local authorities and universities. Where a filing room is full, the answer is usually a different arrangement of the same floor area rather than more cabinets.