Protect migrated data with access controls and backups
Limit who can alter conversion files, preserve source records and maintain traceable changes throughout the transfer.
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 conversion file contains customer bank details. Which access approach is safest?
What you will learn
- Apply role-based access and separation of duties
- Protect conversion files and backups
- Maintain audit trails that identify who changed data and why
Limit access to the data and conversion tools
Grant each project role only the access needed to extract, map, import, review or approve records. Separate preparation from approval where practical and remove temporary access when conversion ends. Protect files containing payroll, customer or supplier details from unauthorised viewing or copying.
Use controlled storage, secure transfer methods and access logs. Test restore procedures for backups rather than assuming a saved file can be recovered. Keep a protected copy of the original data and the conversion mapping so corrections remain traceable.
Preserve a complete change history
An audit trail records the source, user, date, change, reason and approval for material migration corrections. Preserve failed imports and exception reports too; removing them can hide repeated errors or unresolved data problems.
Backups support recovery from loss or corruption but do not replace validation or reconciliation. Access control, encryption where appropriate, secure storage and review reduce the risk of data being altered or exposed during migration.
Pause and explain
What does a backup protect against, and what does it not prove?
Worked example
A contractor needs to map account codes for a week. State two access controls and two audit-trail records the finance team should require.
Show the worked solution
- Give time-limited access to only the mapping area and source fields required for the task.
- Require separate internal review/approval before the contractor's mappings can be imported; revoke access after the work.
- Record the contractor, date, source and destination codes, changes, reasons and reviewer approval.
Answer Limit the contractor's access and duration, require internal approval before import, and log each mapping change with its source, reason and reviewer.
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.
A user has permission to import data and approve the same import. Explain the conflict and propose one role change.
Give me a hint
Consider the risk that an error could be introduced and approved by one person.
Compare my reasoning
- The user can prepare and approve their own work, reducing independent challenge.
- Separate import preparation from approval where practical.
- Assign a reviewer with appropriate access to approve the totals, exceptions and reconciliation before the batch is accepted.
Separate preparation and approval so an independent reviewer checks the import and its evidence before acceptance.
Look for these in your work
- The user can prepare and approve their own work, reducing independent challenge.
- Separate import preparation from approval where practical.
- Assign a reviewer with appropriate access to approve the totals, exceptions and reconciliation before the batch is accepted.
An import log records 14 changed account mappings but names only the administrator account and has no reasons. Identify three audit-trail gaps and a remediation.
Give me a hint
A generic account does not identify the person; each change also needs context and approval.
Compare my reasoning
- The log does not identify the individual user who made each change.
- It omits the source/destination details or the reason and approval for each mapping change.
- Use named accounts, retain before/after values and require a correction record with reason, date and reviewer.
The trail lacks individual attribution, change detail/reason and approval. Preserve the file, reconstruct evidence where possible and use named access with complete change logs going forward.
Look for these in your work
- The log does not identify the individual user who made each change.
- It omits the source/destination details or the reason and approval for each mapping change.
- Use named accounts, retain before/after values and require a correction record with reason, date and reviewer.
A project lead proposes overwriting the original source extract with corrected values to avoid keeping two files. Explain the record-integrity risk and a safer method.
Give me a hint
Keep an immutable source copy and place corrections in a traceable working version.
Compare my reasoning
- Overwriting removes the baseline needed to verify what changed and to trace values to original evidence.
- Store the original securely as read-only and create a controlled working copy for approved corrections.
- Log each change, protect access, back up both versions and reconcile the approved output to the original source totals.
Retain a protected read-only original and apply changes to a controlled copy with a complete change log, backups and reconciliations.
Look for these in your work
- Overwriting removes the baseline needed to verify what changed and to trace values to original evidence.
- Store the original securely as read-only and create a controlled working copy for approved corrections.
- Log each change, protect access, back up both versions and reconcile the approved output to the original source totals.
Common mistakes
- Giving a contractor unrestricted administrator access
- Assuming a backup is useful without testing restoration
- Deleting failed import logs after fixing the final batch
What can you explain now?
Why keep an audit trail of conversion changes?
Compare with the explanation
To show who changed what, when, why and with whose approval
A traceable change history supports review and helps investigate differences after go-live.
After trying it yourself, choose your next review. This is your self-assessment.
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Make it stick
Name three controls that protect migrated data from unauthorised changes or loss.
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.