Map the chart of accounts and data fields
Translate old ledger codes into the new system's account structure without changing the meaning or sign of balances.
Section 3.4 · Computerised accounting systems
Exam scope and assessment notes
Cambridge International AS & A Level Accounting 9706, 2026–2028 syllabus, Version 2. These lessons cover the process of transferring business accounts to a computerised accounting system and ways to maintain data integrity during conversion. No specific accounting application is required. Practice is self-checked, not an official Cambridge grade. Full timed Papers 1–4 and human subject-teacher review remain outstanding.
Before you begin
- Use the Topic 1.2 accounting-system skills: understand double entry, trial balances, control accounts, source documents and why complete records matter.
Work on paper. Try each question before revealing help, and explain why your method works.
Quick readiness check
A new account code has the same number as an old account but a different description. What should the mapper compare?
What you will learn
- Map source accounts and fields to the new chart
- Document one-to-one and many-to-one mappings
- Test that classifications, signs and reporting groups remain correct
Map meaning, not just account numbers
A new chart of accounts may use different codes or groupings from the old ledger. Create a mapping table showing each source code, destination code, description and reporting classification. A code number alone does not prove that two accounts represent the same kind of balance.
Several old accounts may map to one new summary account if the new system is designed to combine them, but preserve sufficient detail for control, reporting and audit needs. Where one source account must split across destinations, obtain a supported allocation basis and approval rather than choosing a convenient percentage.
Test signs, categories and totals
Check whether debit and credit balances keep the expected sign and whether current/non-current, income/expense and control-account classifications remain correct. Map fields such as customer ID, invoice date, currency and tax code as well as ledger codes.
Run a test import, compare mapped account totals and review financial-statement classifications. A trial balance can still balance while an account is misclassified, so combine arithmetic checks with description and reporting checks.
Pause and explain
Two old expense accounts map to one new account. What should be checked before the detail is combined?
Worked example
The old system has separate codes for office rent $24,000 and warehouse rent $36,000. The new system has one rent account. Explain a suitable mapping and a reporting risk to consider.
Show the worked solution
- Map both source codes to the new rent account if the approved reporting design combines them.
- Document both source-to-destination relationships and preserve the original detail in the migration record.
- Check whether management still needs office-versus-warehouse analysis; if so, retain dimensions or subaccounts rather than losing the distinction.
Answer Both accounts can map to the new rent account if approved, but retain a reporting dimension if users need to analyse the two locations separately.
Try a topic test
Choose Easy, Normal or Difficult. Save your answers and open worked review after finishing.
Test this topic →From guided practice to a new situation
Write your answer and reasoning first. Use a hint only if you are stuck. The model solution is for self-checking; your written work is not automatically marked.
Old receivables control is $48,000 debit; a new system maps it to trade receivables. Old sales returns of $3,200 debit are mapped to revenue by mistake. Identify the control and classification checks.
Give me a hint
An arithmetically balanced transfer can still misclassify a contra-revenue balance.
Compare my reasoning
- Check the $48,000 debit receivables balance maps to the correct control account and agrees with the customer subledger.
- Check sales returns remain a contra-revenue or returns account, not ordinary revenue.
- Compare the mapped trial balance and statement presentation with source descriptions and the approved mapping table.
Reconcile receivables control to the customer subledger and correct the sales-returns mapping to the approved returns classification; then recheck totals and presentation.
Look for these in your work
- Check the $48,000 debit receivables balance maps to the correct control account and agrees with the customer subledger.
- Check sales returns remain a contra-revenue or returns account, not ordinary revenue.
- Compare the mapped trial balance and statement presentation with source descriptions and the approved mapping table.
Four source expenses of $1,800, $2,600, $3,400 and $2,200 map to one new repairs account. Calculate the mapped total and state two controls that preserve detail and accuracy.
Give me a hint
Add all source balances and document the many-to-one mapping.
Compare my reasoning
- Total mapped repairs balance = $1,800 + $2,600 + $3,400 + $2,200 = $10,000.
- Retain the source-code detail or an approved analysis dimension in the migration record.
- Reconcile the $10,000 new-account balance to the four source accounts and have the mapping independently reviewed.
Mapped total $10,000. Preserve the source detail, reconcile the four balances and obtain an independent review of the mapping.
Look for these in your work
- Total mapped repairs balance = $1,800 + $2,600 + $3,400 + $2,200 = $10,000.
- Retain the source-code detail or an approved analysis dimension in the migration record.
- Reconcile the $10,000 new-account balance to the four source accounts and have the mapping independently reviewed.
The new system presents a supplier deposit as an expense because its code was mapped to purchases. Explain the likely user impact and the correction process.
Give me a hint
The balance's nature and period matter; check the source description and financial-statement category.
Compare my reasoning
- A supplier deposit may be a prepayment or asset rather than an expense until goods or services are received.
- Misclassification can understate assets and overstate current expenses or distort profit.
- Review the source documentation, correct the mapping through an approved change, rerun the trial balance and recheck reporting outputs.
Correct the account to the appropriate deposit or prepayment category based on the evidence; review the effect on profit and assets and document approval and retesting.
Look for these in your work
- A supplier deposit may be a prepayment or asset rather than an expense until goods or services are received.
- Misclassification can understate assets and overstate current expenses or distort profit.
- Review the source documentation, correct the mapping through an approved change, rerun the trial balance and recheck reporting outputs.
Common mistakes
- Mapping by similar code number rather than account meaning
- Splitting balances without a supported basis
- Assuming a balanced trial balance proves correct classification
What can you explain now?
What should a source-to-destination mapping table show?
Compare with the explanation
Source code, destination code, meaning and approved rule
The table makes the transfer traceable and lets reviewers check that balances retain their intended classification.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Why can a trial balance balance while the chart-of-accounts mapping is still wrong?
If you needed the solution, close it and solve the problem again from a blank page. A correct answer is stronger when you can explain the reason for each step.