Mapping is the first mechanical step of fieldwork and the source of the file's integrity. Every trial balance account is assigned to a financial statement line and a lead schedule. Done well, the totals tie by construction, and the work in each area builds on a solid base. Done carelessly, accounts drop out, signs flip and the financial statements fail to foot. For the underlying documents see trial balance, lead schedules and adjusted trial balance worksheet.
Step 1: Get the right trial balance
Request the unadjusted trial balance as of the balance sheet date, in electronic form, directly from the accounting system, with account numbers, names and balances. Ask for the same for the prior year and for the opening balance. Also request the detail general ledger for the year, since it will be needed for entry testing.
Record the source, who ran it, the date and time, and the settings (basis, closed periods). If the client emails a spreadsheet they typed or edited, ask for a system-generated report instead.
Step 2: Tie out before mapping
Before any mapping, prove the import:
- Debits equal credits. The trial balance sums to zero.
- Net income per the trial balance agrees to the income statement the client provided and to retained earnings activity.
- Prior-year closing balances equal current-year opening balances.
- Account count and total debits match the source report footer.
- Prior-year balances agree to the prior-year audited financial statements.
If the opening balances do not equal prior-year audited amounts, find out why before going further. It may be a subsequent adjustment, a restatement, a change in the chart of accounts, or an error. The audit opening balance depends on it. See first-year audits and opening balances.
Step 3: Design the map
The map table has one row per account with these columns:
| Column | Content |
|---|---|
| Account number | From the client system |
| Account name | From the client system |
| Type | Asset, liability, equity, revenue, expense |
| Financial statement line | The caption on the face of the statements, such as "Trade receivables, net" |
| Lead schedule | Reference such as E-1 |
| Sub-lead or grouping | For example "cash, operating" versus "cash, restricted" |
| Current or noncurrent | For balance sheet accounts |
| Cash flow category | Operating, investing, financing, or noncash, to support the cash flow statement |
| Normal balance | Debit or credit |
| Tax code | If the engagement supports tax |
| Related party flag | Yes or no |
Build the map once and save it as a template with each client. The following year's mapping is a rollover plus new accounts.
Step 4: Map every account
Walk each account. Rules that avoid common errors:
- Contra accounts follow their parent. Accumulated depreciation maps to the same lead schedule as property and equipment. The allowance for credit losses maps with receivables.
- Clearing and suspense accounts get a map and a question. A balance in "uncategorized" is a lead for follow-up, not a mapping decision.
- Accounts with both debit and credit balances in different periods need a flag. Customer credit balances in receivables should be reclassified to liabilities for presentation, which is a reclassification entry.
- Intercompany and due-to or due-from accounts map to their own lead and need an elimination check if there are multiple entities.
- Debt maps to current and noncurrent by schedule, not by the account name. The map may split a single ledger account across two lines, through a sub-account or an entry.
- Revenue and expense accounts map to the income statement line, but remember that cost of sales, operating expense and other income separation drives the classified presentation.
Step 5: Add subtotals and the footing
Create subtotals for each lead schedule and for each financial statement line. Total assets must equal total liabilities plus equity, and net income must flow to retained earnings.
Check that the totals by financial statement line add to the trial balance total by type:
| Check | Expected |
|---|---|
| Sum of all mapped accounts | Zero |
| Sum of asset lines | Total assets per balance sheet draft |
| Sum of liability and equity lines | Equals total assets |
| Sum of revenue and expense lines | Net income per the income statement |
| Unmapped accounts | None |
| Accounts mapped twice | None |
Step 6: Roll the map forward
Each year, import the new trial balance into the saved map. Then list:
- New accounts, which have no map yet.
- Accounts present in the prior year and missing in the current year, which may be renamed or merged.
- Accounts with different names but the same number.
- Accounts whose balances change sign.
Handle each by hand. The rollover is where silent mapping failures happen, because the old map hides new accounts in totals.
Step 7: Build lead schedules from the map
Each lead schedule picks up the mapped accounts with columns for prior year, current year unadjusted, adjustments, adjusted, and references to the workpapers that support each account. The lead schedule is a formula-driven view of the map, not a retyped copy. If staff retype balances, errors creep in.
Step 8: Keep the map in sync with adjustments
Entries on the adjusting entry log post into the map by account. New accounts created by an adjusting entry need a map row. Reclassifications that change presentation need a note in the map.
Worked example
An import of a services company shows 214 accounts. The tie-out:
- Total debits $18,436,200, total credits $18,436,200. Footing agrees.
- Net income per trial balance $1,204,300, per the client's income statement $1,204,300.
- Opening balances agree to the prior-year audited balance sheet except retained earnings: trial balance opening $3,801,000 versus audited $3,815,000. The difference of $14,000 is a post-closing entry the client booked in the first month. It is tracked as an item for follow-up. The prior-year audit file shows it as a passed adjustment.
Mapping results: 3 accounts have no map ("Misc clearing," "Owner draws," "Loan from shareholder"). Misc clearing has a $22,000 credit balance, which turns out to be unapplied customer payments. It maps to a liability (customer deposits), not to receivables. Owner draws map to equity. Loan from shareholder maps to related party debt with a flag. After the fixes, the mapped totals foot to the draft statements.
Common failures
- Mapping by account number range instead of reading the account.
- Leaving credit-balance receivables in assets.
- Ignoring the cash flow statement category, which causes a scramble later.
- Overwriting the map after audit entries instead of adding a row.
- Using the prior year's map without checking for renamed accounts.
Documentation checklist
- Source and tie-out of the trial balance.
- The map table, version-controlled.
- Unmapped accounts at zero, evidence of the check.
- Opening balance agreement to prior-year audited statements.
- Lead schedules linked to the map.
CORAA prepares ready-to-review audit files for US CPA firms; the firm keeps the client, the review and the signature. See /us.
Sources
- AICPA, AU-C Section 230, Audit Documentation; AU-C Section 510, Opening Balances: Initial Audit Engagements, Including Reaudit Engagements
Part of CORAA University · Working papers and documentation: related guides, calculators and templates.
AU-C references are to AICPA Professional Standards, paraphrased here; read the standard itself before relying on a requirement. This page is guidance, not professional advice. Report an error