Accounting workpapers and audit trail: what bookkeepers should keep

Two years after a month-end, someone asks why the VAT control account showed the balance it did. It might be the client’s accountant, a new bookkeeper taking over, a lender, or the tax authority. If the answer is “it was reconciled at the time”, you have nothing. If the answer is a one-page schedule with the return workings attached, the conversation is over in five minutes. That page is a workpaper, and the habit of producing it is what separates bookkeeping that can be defended from bookkeeping that has to be redone. This guide covers what the ledger records for you, where its record stops, and a monthly file that fills the gap. Software facts are linked in the Sources section.

Three layers of evidence

Bookkeeping evidence comes in three layers, and each answers a different question.

Most files have the first layer in patches, the second by accident, and none of the third.

Layer 1: source documents

Every purchase should carry its bill or receipt, every sale its invoice, every journal its calculation. The document belongs on the transaction itself, not in a folder that someone has to search. A reviewer opening the transaction should see the evidence without asking.

How long documents must be kept, and whether a digital copy is enough, is set by each tax authority. The country guides cover it: UK, Australia, New Zealand, Canada, and Singapore.

Layer 2: what the ledger records for you

Xero

Every transaction in Xero carries its own history. Each time someone creates, edits, or adds a note to a transaction, an entry is added with the user’s name and the date and time. Entries created automatically, such as repeating invoices, show the user as System Generated ^[1] .

For the whole organisation there is the History and notes report, which Xero itself describes as what is sometimes called an audit trail or audit log. It lists changes to transactions, contacts, inventory items, fixed assets, and financial settings, filterable by date, user, and type, and exportable as PDF or Excel ^[2] . Its limits matter:

• Only users with the administrator role can open it.
• Results display up to a maximum of 1,000 per search, so narrow the date range.
• It does not include changes to payroll transactions or expense claims ^[2] .

QuickBooks Online

QuickBooks Online has the audit log, opened from Settings. It records sign-ins, changes to settings, edits to customers, vendors, and employees, and changes to transactions including deletions. Each entry shows the date, the user, and the details, and the log can be filtered by user, date, and event. It cannot be turned off ^[3] .

The limit that catches people out: QuickBooks states that events recorded in the audit log are available for two years ^[3] . Record-keeping obligations run longer than that in every country this site covers. If you may need to show who changed a transaction three years from now, the audit log will not do it for you.

Where the ledger’s record stops

The audit trail tells you that a transaction changed. It does not tell you whether a balance was right. And some of what the ledger stores can be removed: QuickBooks warns that undoing a reconciliation permanently deletes the associated reports and attachments ^[4] . Evidence that exists only inside the ledger is evidence someone else can remove. That is the case for the third layer.

Layer 3: the monthly workpaper file

A workpaper file proves the balance sheet at a date. Build one per client per period, with the same sections in the same order every time.

The software produces much of the evidence. In Xero, the Reconciliation Reports pack runs the Trial Balance, Aged Receivables Summary, Aged Payables Summary, a Bank Reconciliation Summary for each active bank account, Fixed Asset Reconciliation, General Ledger Exceptions, and the Journal report for one date range ^[5] . The Bank Reconciliation Summary shows the balance in Xero, outstanding items, unreconciled statement lines, and the statement balance ^[6] . In QuickBooks Online, each completed reconciliation saves a report under History by account ^[7] . Export these as PDFs on the day you close and file them.

What makes a workpaper good

A reviewer who was not there should be able to follow it without asking you anything.

• It stands alone. Client, period, account, preparer, date, and source of every figure are on the page.
• It ties. The total agrees to the trial balance, and the page says so.
• Differences are itemised. “Difference 412.80: three items, listed below” is a reconciliation. “Difference 412.80, immaterial” is a hope.
• Judgements are written down. If you accrued an estimate, the basis is stated.
• It is frozen. Save a PDF dated at the close. A live report regenerated next year will show different numbers if anything was changed.

Manual journals

Manual journals are the weakest point in any audit trail, because they have no natural source document. Give every one three things: a narrative that says why, the calculation or document attached, and the name of whoever approved it. The Journal report in the Xero pack, or a journal listing in QuickBooks, is section J; go through it line by line each month and make sure nothing is unsupported.

Naming and filing

Pick one convention and never vary it. For example:

• Folders: Client, then year, then period.
• Files: period, reference, description. “2026-03 A1 Bank rec current account.pdf”, “2026-03 D1 VAT control rec.xlsx”.

The test of a filing system is whether someone else can find March’s VAT reconciliation for any client in under a minute.

Review and sign-off

Section R records that someone looked. It holds the variance notes from the review step of the month-end close process, the queries raised and the client’s answers, and the name and date of the preparer and the reviewer. In a one-person practice, sign it yourself on a different day from the preparation. A second look, even your own, catches what the first missed.

The year-end handover pack

If someone else prepares the annual accounts, twelve good monthly files make the handover an afternoon’s work. Send:

• The final trial balance and the twelve section A to H lead schedules for the last month.
• Bank statements and reconciliations at the year-end date.
• The fixed asset register, with additions and disposals for the year and their invoices.
• The journals listing for the year with support.
• VAT or GST reconciliation for the year: returns filed against the control account.
• Payroll year-end reports.
• A note of anything unusual: disputes, write-offs, items in suspense, changes of accounting treatment.

Retention

Keep workpapers for at least as long as the underlying records must be kept; the country guides linked above give those periods. Two further points. First, agree in the engagement letter who owns the working papers and what is handed over if the engagement ends. Second, some obligations are yours, not the client’s: in the UK, a supervised bookkeeper must keep customer due diligence records for 5 years from the date the business relationship ends ^[8] .

Common gaps

• Bank reconciliations done but the report never saved.
• A VAT or GST control account that has not been agreed to a return for a year.
• Accruals with no schedule, carried forward because nobody knows what they are.
• Manual journals described as “adjustment”.
• Evidence held only inside the ledger, by an administrator who could delete it.
• A file structure that differs for every client.

Where ExpenseFlow fits

ExpenseFlow works on the first layer and part of the second, for purchases. When an approved bill or receipt syncs to Xero, the original document is attached to the transaction and the capture and approval history is written into its history and notes, so a reviewer opening the bill in Xero sees the image, who captured it, and who approved it. A transaction synced to QuickBooks Online carries a note with its ExpenseFlow reference; the document and its history are held in ExpenseFlow. Captured images are stored hashed and timestamped, so the copy behind a posted transaction can be shown to be the one that was captured. Review happens through roles and per-row approvals before anything reaches the ledger.

It does not build the third layer. ExpenseFlow does not produce reconciliations, lead schedules, or journal support. Sections A to R remain the bookkeeper’s file.