What it means
In accounting, reliability means that financial statements fairly show the transactions they claim to describe. Accounting frameworks today often speak of faithful representation, which means complete, neutral and free from material error, and the older word reliability is still used in everyday conversation.
For a non-specialist, the two ideas amount to the same thing: can I trust this number? Information is more reliable when it can be traced to evidence such as invoices, bank statements and contracts.
It is also more reliable when two independent people would reach the same figure from the same facts, which is called verifiability. A number that rests on one person's opinion is weaker.
Reliability matters because every other use of the numbers depends on it. A lender reading accounts, a manager setting a budget and an investor valuing a company all assume that the underlying data can be trusted.
Once that trust is lost, it takes years of clean reporting to rebuild. There is often a trade-off with relevance.
A fresh estimate of the value of an asset may be more relevant to a decision but less reliable than the original cost shown on an invoice, so accountants must judge the balance. Clear notes to the accounts explain which approach was used and why.
Reliability applies outside the accounts too. A forecast model is reliable if it has a track record of landing close to actual results, and a data feed is reliable if it is complete and updated on time.
Controls build reliability. Examples include approvals, reconciliations (matching two records to find differences), segregation of duties and independent audit, all of which reduce the chance that errors or manipulation go unnoticed.
Good controls are cheaper than correcting mistakes after the accounts are published.
In practice
Real-world examples
Example 1
A retailer reconciles its bank statement to its cash book every month and finds a $4,500 payment recorded twice. The correction makes the cash balance reliable before the accounts go to the bank. The lender approves its renewal on the strength of the cleaner numbers, and the retailer adds the check to its month-end routine.
Example 2
A property developer values land at its original purchase price of $1,500,000 supported by a signed contract, rather than at an agent's opinion of $2,100,000. The lower figure is easier to verify and therefore more reliable. The auditors accept it without further queries, although the notes to the accounts mention the agent's opinion for context.
Example 3
A subscription business finds that its monthly forecast is within 3% of actual revenue in eleven months of the last twelve. Because the model has a good track record, the board uses it to set hiring plans. The finance team keeps a log comparing forecasts to actual outcomes, and it reviews the log whenever the model's assumptions change.
Think of it
Reliability is like a kitchen weighing scale. If the scale is calibrated correctly, you get the exact amount of flour needed for your recipe every time, allowing you to bake with confidence.
Case study
Seen in the real world
Quayside Components is an illustrative, fictional manufacturer that reported profit of $1,200,000 for the year. During the audit, the auditors found that $350,000 of stock counted at year end had no supporting count sheets.
Without evidence, the stock figure could not be relied on, and the auditors asked for a recount. The recount showed that $90,000 of stock had been double counted, and profit was restated to $1,110,000. The directors were embarrassed, but the bank was more concerned about the weak controls than the lower profit.
The company introduced numbered count sheets, signed by two people, and a rule that stock records are reconciled to the general ledger every quarter. In this illustrative story, the improved controls made the next audit shorter and the figures more trusted by the bank. The finance director also reported the number of corrections found in each month-end close to the board. A falling count became a simple measure of whether the reliability of the accounts was improving.
Watch out
Common mistakes
- Assuming that numbers from a computer system are reliable simply because they are precise, when they can be precisely wrong if the input was wrong or a formula was copied incorrectly.
- Treating reliability and accuracy as the same thing, when reliability also covers consistency, evidence and freedom from bias in how the figures are chosen and presented.
- Choosing the most up-to-date estimate over verified figures without considering how much uncertainty it carries, particularly for assets with no active market.
Questions
People also ask
What makes financial information reliable?
It is supported by evidence, free from material error, neutral in presentation and consistent from one period to the next. Independent review adds further assurance.
How is reliability different from relevance?
Relevance means information helps a decision, while reliability means it can be trusted, and the two sometimes pull in different directions. Good reporting aims to give both.
How can a business improve reliability?
By strengthening internal controls, keeping evidence for transactions, reconciling regularly and having figures reviewed independently. Training staff to record transactions the same way every time also helps.