Chart of Accounts: Read Codes and Map Changes

What a Chart of Accounts Defines

The chart lists the accounts available for posting and groups them into a hierarchy. The transactions posted to those accounts appear in the general ledger. Balances show the amounts accumulated at a particular point.

The Australian Accounting Standards Board’s AASB 101 presentation guidance identifies assets, liabilities, equity, income and expenses as financial-statement elements. Its aggregation rules distinguish items by nature or function. These classes help interpret an account, but the account numbers remain specific to the entity and system. There is no universal Australian code number that makes every account 200 a loan.

A Fictional Company Chart

The following simplified chart belongs to fictional company Wattle Services. Its numbers illustrate one company’s structure.

An account class is a broad classification, such as liability. A control account, such as trade receivables, summarises balances supported by customer-level detail. A tracking dimension, such as branch or project, adds an analytical label to an entry. Keep that dimension separate when combining accounts so a branch label does not become a new account class.

Collect the Original Structures

Request the chart used in each entity, system and period, including inactive accounts. A current chart can omit a code that still appears in earlier records.

1. Obtain the original exports with code descriptions, account classes and parent-account relationships. Keep account codes as text so leading zeroes survive.
2. Identify each chart’s effective period and version. Request available change logs, migration schedules and evidence of account renaming or reclassification.
3. Retain the original code and label beside the entity, source system and relevant period in your working schedule.
4. Compare the chart with the codes actually used in the supplied records. Record any posted code missing from the chart as an exception.

Use that combined identity whenever you look up an account. Wattle’s code 200 and another company’s code 200 can have different meanings. A reused code within Wattle also needs separate period-specific identities if its meaning changed.

Map Codes Without Losing Their Meaning

Build a crosswalk that records each proposed match and why it is supported. Keep the crosswalk separate from the original export so you can change the mapping without overwriting evidence.

For Wattle’s old chart, the minimum working fields look like this. The source entity and period apply to every row and remain explicit columns in the working file.

A one-to-one match changes the destination code while preserving the account’s meaning. Many-to-one mapping aggregates several source accounts, such as two premises-rent accounts, into one destination. Retain each source row so the combined amount can be traced back.

A split account needs an allocation supported by underlying records. A code whose meaning changed needs separate rules for each relevant period. A shared label such as “Loan” does not establish the borrower, lender or direction of the balance.

Splitting the Combined Loan Account

In this fictional example, Wattle’s old account 200 combines director and external-lender borrowings. The new structure separates them. The opening credit balance is $20,000 and the closing credit balance is $24,000.

The supporting schedules attribute opening balances of $8,000 to the director and $12,000 to the external lender. They attribute closing balances of $9,000 and $15,000 respectively. Each schedule connects to its agreement and the relevant advances or repayments in the bank records.

Incorrect mapping: copy the whole $20,000 opening balance into both new accounts. That produces $40,000 of opening borrowings.

Correct mapping: allocate $8,000 and $12,000 to the two accounts. Their opening balances still total $20,000. Allocate the closing amounts separately, preserving the $24,000 closing total.

A fixed opening percentage is unsuitable when later transactions belong to different lenders. If $3,000 of the closing balance has no supported allocation, retain that amount as unresolved within the loan class. Record the evidence needed to allocate it.

Test the Mapping Against Transactions

Test each proposed mapping with representative postings and supporting records before accepting its classification. Select entries around the change as well as an ordinary entry from each affected account.

For Wattle’s loan split, compare the opening schedules with the agreements, then trace selected advances and repayments to payment evidence. For rent, inspect invoices and the corresponding entries. For trade receivables, compare customer-level detail with the control-account balance. Investigate a difference before treating it as a mapping adjustment.

Use the general ledger when the test needs the posting sequence or journal context. A chart alone cannot show which transactions created a balance.

An accounting-code mapping assigns recorded entries to the combined accounting structure. A bank-transaction category describes a movement in a bank account. A payment categorised as a loan repayment still needs evidence identifying the loan and separating principal from any interest.

For the bank-evidence stage, FinTrace saves forensic accountants hours of statement conversion and review. You receive a searchable, categorised Excel ledger and a findings report with direct source references. Use that payment evidence alongside the accounting records when testing the crosswalk. Keep bank categories in their own fields beside the mapped accounting codes.

Neither a mapped code nor a bank category alone establishes ownership, tax deductibility or an enforceable debt. Record the evidence supporting those separate conclusions where they form part of your instructions.

Reconcile Totals and Preserve Exceptions

Compare the original and mapped balances at both ends of the period. Use the same entity coverage, currency and sign convention on each side.

Wattle’s Before-and-After Check

This fictional schedule uses separate debit and credit totals. Opening income and expense balances are zero. The original closing balances include bank $25,000 debit, receivables $12,000 debit and rent $8,000 debit. Closing credits comprise loans $24,000, payables $6,000, equity $5,000 and service income $10,000.

The remaining original opening balances are bank $20,000 debit, receivables $10,000 debit, payables $5,000 credit and equity $5,000 credit. All unchanged accounts map once. An intentional split creates two allocation rows, each with its own amount.

Copying the entire loan balance to both destinations raises opening credits to $50,000 and closing credits to $69,000. Dropping the external-lender allocation instead reduces those totals to $18,000 and $30,000. Both errors break the balance reconciliation.

A balanced result can still contain a wrong classification. Compare totals by account class and check every source account’s allocation sum against its original balance. Use a trial balance for the balance-level tie-out. Interpretation of the resulting reports belongs in financial statement analysis.

Keep the untouched export, mapping version and allocation rules with the combined schedule. Retain supporting document references and an exception list showing each unresolved amount, reason and required evidence. Give the reviewer enough detail to reproduce the same totals without guessing which version or allocation you used.