Bookkeeping workpapers are the records that show how a client's month was closed: the bank and card statements, the reconciliation proving each balance, the review notes, the client's answers to your questions and any adjusting entries with their support. Keep one set per close, filed by client and period, so anyone can retrace the month later.
What are bookkeeping workpapers for a monthly close?
Bookkeeping workpapers for a monthly close are the evidence behind the numbers. The ledger says what the books contain. The workpapers say why: which statement each balance came from, who checked it, what the client confirmed and which entries were made by judgment rather than from a bank line.
Who reads them
- You, next month. The prior month's reconciliation and open items are the starting point for the next close.
- A reviewer. On a team, the reviewer reads the workpapers instead of redoing the work.
- The client's tax preparer. At year end, preparers ask how a balance was reached, and the workpapers answer without a search.
- Whoever takes over. If the client moves to another bookkeeper, a clean set of workpapers makes the handover short.
What they are not
Workpapers are not a copy of everything the client ever sent. Receipts, invoices and contracts are the client's source documents, and they may live in the client's own systems. A workpaper refers to a source document where one supports an entry, but the workpaper file itself should hold the records that prove the close, not every file in the inbox.
Which bookkeeping workpapers belong in each client close?
Each client close needs a small, fixed set of workpapers: the statements for every account, a reconciliation report per account, a list of adjusting entries with support, the review record and the client question log. The set should be the same every month so a missing item stands out.
The workpaper set
The table below is a minimum set for a typical small-business client. Add to it for clients with payroll, inventory or sales tax.
| Workpaper | Source | What it proves |
|---|---|---|
| Bank and card statements, every page | Client or bank | The external record the books are tested against |
| Converted transaction rows | Conversion output | Each line that was posted, with date, amount and description |
| Reconciliation report per account | Accounting software | The book balance equals the statement closing balance |
| Adjusting entries list | Bookkeeper | Every entry not taken from a bank line, with its reason |
| Support for adjustments | Loan schedule, payroll report, invoice | The figure behind each adjustment |
| Client question log | Email or messages | What was asked, what the client answered and when |
| Review record | Reviewer | Which checks were run, by whom, with exceptions noted |
Why keep the converted rows
The statement PDF is the authority, but the converted rows are what reached the books. Keeping both lets you show line by line that what was posted matches what the bank printed. AutoBankConvert checks each converted statement against its own opening and closing balance before it is marked done, and that passed check is itself a useful line in the workpaper file.
Owner and personal items
When a client runs personal spending through a business account, the workpapers should show how each personal line was treated and what rule the client agreed to. The method is in sorting commingled personal and business transactions, and the agreement belongs in the client question log.
Balance proof workpapers when the statement period is not the month
A balance proof workpaper shows the book balance agreeing with a bank balance on a stated date. When a statement runs from the 16th to the 15th, the closing balance on the statement is not the month-end balance, so the proof needs one extra line explaining how the month-end figure was reached.
Two ways to document it
- Reconcile to the statement date. Reconcile the books to the statement's closing balance on the 15th, and note that the rest of the month is covered by the next statement.
- Roll to month end. Start from the statement's closing balance, add and subtract the transactions from the 16th to the 31st from the next statement, and show the resulting month-end balance.
Either is acceptable if it is written down and used consistently. What fails is a reconciliation dated the 31st against a balance that was really the 15th. Statement periods that are not a calendar month works through the cutoff in detail.
Year end needs the roll
At a fiscal year end, the balance sheet date is fixed. Whatever you do in other months, the year-end workpaper should prove the balance on the last day of the year, which usually means the roll-forward method.
Review notes and client answers kept as workpapers
Review notes and client answers are workpapers because they record the judgment behind entries that a statement cannot explain. A deposit coded as a loan rather than sales, a charge moved to owner draws, a supplier reclassified to cost of goods: each rests on a conversation. Without the record, the entry looks like a guess.
What to save from a client conversation
Save the question as you sent it, with the transaction's date, amount and description, and save the reply as written. A one-word answer such as "personal" is enough when it is attached to the line it answers. Paraphrasing later loses detail and, if the entry is challenged, loses the client's own words.
What to save from a review
The review record should list each check, a tick or an exception, the reviewer's name and the date. Exceptions need a short reason, such as "Contract labor up 40 percent, new subcontractor confirmed by client." That line saves the next reviewer the same question.
A folder layout for a client's yearly workpapers
A workable folder layout puts each client in its own folder, each fiscal year inside that, and each month inside the year, with the same file names every month. A fixed layout means anyone in the practice can find a reconciliation in seconds, and a missing file is visible because its slot is empty.
An example layout
The names below are an example. The point is that they never change from month to month.
Client - Example Bakery LLC/
FY2026/
2026-01/
statements/ checking-4417_2026-01.pdf, card-0921_2026-01.pdf
rows/ checking-4417_2026-01.csv
reconciliations/ checking-4417_2026-01_rec.pdf
adjustments.pdf
questions.pdf
review.pdf
2026-02/
...
year-end/
balance-proofs.pdf
preparer-package/
permanent/
engagement-letter.pdf
account-list.pdf
opening-balances.pdf
The permanent folder
Some records apply to every year: the engagement letter, the list of accounts and their cycle dates, opening balances and the client's standing rules. Keep them in a permanent folder outside the yearly ones, and update it when anything changes.
Using workpapers to price your work
Workpapers also show how much effort each client takes. A client whose question log runs to two pages every month is a different job from one with three questions. That evidence matters when you set or defend fees, including whether a reduced rate for a client makes sense, which is weighed in should bookkeepers offer discounts.
How long should bookkeeping workpapers be kept?
Bookkeeping workpapers should be kept at least as long as the records they support might be needed for a tax question. The IRS's general rule is three years from filing, with longer periods in some cases, so many practices keep workpapers for longer than three years and set the period in the engagement letter.
The IRS periods
The IRS page How long should I keep records? gives the periods that apply to the records your workpapers support. Records generally should be kept three years. The period is six years if income was underreported by more than 25 percent of gross income, seven years for a claim for a loss from worthless securities or a bad debt deduction, and at least four years for employment tax records after the tax is due or paid.
Set your own policy
Those periods describe what a taxpayer may need. Your practice's own policy should cover them and say what happens when the engagement ends: whether you return the workpapers, keep copies, or delete them after a set time. Write it into the engagement letter so the client knows.
Workpaper files that are too thin or too thick
Workpaper files fail in two directions. A thin file holds the ledger and little else, so nobody can show how a balance was proven. A thick file holds every email and attachment, so the proof is buried. Both make the next close, review or handover slower than it needs to be.
Signs of a thin file
- Reconciliations marked complete in the software, but no saved report.
- Adjusting entries with no note of where the figure came from.
- Client answers that exist only in someone's memory.
A thin file usually looks fine until someone asks a question. The test is to pick a balance at random and try to prove it from the folder alone, without opening the accounting software or asking the person who did the work. If you cannot, the file is too thin.
Signs of a thick file
- Duplicate statements in several versions with no indication of which was used.
- Whole email threads saved when one reply mattered.
- Files named by download date instead of account and period.
Make the set automatic
The fix for both is a fixed set produced the same way every month. Much of it can come straight from tools: statements and rows from conversion, reconciliation reports from the accounting software, the review record from a checklist. How to automate bookkeeping covers which of those steps to automate first, and AutoBankConvert handles the statement-to-rows part for every client in one batch.