# Trade Accounting and Reconciliation

> Reconciliation checks that internal records of trades, positions and cash match brokers, custodians and clearing houses. Learn the process, common breaks and fixes.

Source: https://learn.tradelabsai.com/industry/trade-reconciliation/  
Track: The Trading Industry · Level: Advanced · Updated: 2026-10-03  
Publisher: TradeLabs AI (https://tradelabsai.com). Education, not financial advice.  
Cite as: TradeLabs Learn, "Trade Accounting and Reconciliation", https://learn.tradelabsai.com/industry/trade-reconciliation/

Every trade creates records in several places: the trader's system, the broker's system, the clearing house, the custodian and the accounting ledger. Reconciliation is the process of comparing those records and resolving any differences, called breaks. It sounds like back office paperwork, but it is one of the most important controls in trading. Unreconciled breaks have hidden rogue trading, led to wrong risk numbers and caused firms to trade on positions they did not actually have.

## What gets reconciled

| Item | Compared against |
|---|---|
| Trades | Broker confirmations and exchange or clearing records. See [Execution Reports and Trade Confirmations](https://learn.tradelabsai.com/orders/trade-confirmations/) |
| Positions | Custodian, prime broker or clearing statements |
| Cash | Bank and broker cash balances |
| Corporate actions | Dividends, splits and other events applied correctly. See [Corporate Actions, Delistings and Rolls in Backtests](https://learn.tradelabsai.com/research/corporate-actions-in-backtests/) |
| Fees and commissions | Broker invoices and schedules |
| P&L | Risk system versus accounting system |
| Collateral and margin | Amounts posted and received |

## The daily process

1. **Collect records** from internal systems and external statements.
2. **Match** trades and positions by identifiers such as trade IDs, symbols, quantities and prices.
3. **Identify breaks:** differences in quantity, price, date, account or missing items.
4. **Investigate** the cause of each break.
5. **Resolve:** correct internal records or chase the counterparty to fix theirs.
6. **Escalate** old or large breaks to management.
7. **Report** reconciliation status as a control metric.

## Common breaks and causes

| Break | Typical cause |
|---|---|
| Missing trade | Order booked manually and not entered in the system, or a late fill |
| Quantity mismatch | Partial fill recorded as complete |
| Price mismatch | Average price calculation or rounding differences |
| Wrong account | Trade allocated to the wrong fund or sub account |
| Settlement date difference | Wrong settlement cycle applied |
| Corporate action break | Split or dividend not processed on time |
| Duplicate trade | Same fill recorded twice after a system retry. See [Alerts, Error Handling and Reconnection](https://learn.tradelabsai.com/algo-trading/error-handling/) |

**Example: A break that mattered**
A bot's internal records show a position of +300 shares of a stock. The broker's end of day statement shows +500. Investigation finds that a buy order for 200 shares timed out, the bot recorded it as failed, but the broker had filled it. The bot's risk checks had been using the wrong position all afternoon, so its maximum position limit was effectively 200 shares too loose. After the fix, the bot queries the broker for order status before marking any order as failed, and reconciles positions every few minutes during the session, not just at the end of the day. See [Building Trading Bots](https://learn.tradelabsai.com/programming/building-trading-bots/).

## Trade accounting basics

| Concept | Meaning |
|---|---|
| Trade date accounting | Record trades on the day they are executed |
| Settlement date accounting | Record when cash and securities change hands |
| Realised P&L | Profit or loss on closed positions |
| Unrealised P&L | Gains or losses on open positions marked to market. See [Mark-to-Market](https://learn.tradelabsai.com/markets/mark-to-market/) |
| Cost basis methods | FIFO, specific identification or average cost, affecting realised P&L and taxes. See [Trading Taxes and Capital Gains](https://learn.tradelabsai.com/industry/trading-taxes-and-capital-gains/) |

## Why reconciliation is a key control

The Barings and Société Générale rogue trading cases both involved hidden positions or fictitious offsetting trades that proper, independent reconciliation should have caught. Regulators expect firms to reconcile regularly and to separate the people who trade from those who reconcile. See [The Fall of Barings Bank](https://learn.tradelabsai.com/history/the-fall-of-barings-bank/) and [Operational and Model Risk](https://learn.tradelabsai.com/portfolio/operational-and-model-risk/).

## Automation

Firms use reconciliation software that matches millions of records automatically and flags exceptions for human review. Clean data, consistent identifiers and timely statements make the process faster and more reliable. See [Data Pipelines and ETL](https://learn.tradelabsai.com/programming/data-pipelines-and-etl/).

## For individual traders

Compare your journal or trading software with broker statements at least monthly, and check year end tax forms against your own records. Automated traders should reconcile positions with the broker at startup and frequently during trading. See [Record Keeping for Traders](https://learn.tradelabsai.com/industry/record-keeping-for-traders/).

## Frequently asked questions

### What is trade reconciliation?

Comparing internal records of trades, positions and cash with external records from brokers, custodians and clearing houses, and resolving any differences.

### What is a reconciliation break?

A difference between two sets of records, such as a mismatched quantity, price or missing trade, that must be investigated and corrected.

### Why is reconciliation important?

It ensures positions, cash and P&L are accurate, catches errors and fraud early and supports correct risk management and reporting.

Next, learn how P&L is explained by its sources in [P&L and Performance Attribution](https://learn.tradelabsai.com/industry/performance-attribution/).

## Continue learning

- Next lesson: [P&L and Performance Attribution](https://learn.tradelabsai.com/industry/performance-attribution/)
- Previous lesson: [Risk Analyst](https://learn.tradelabsai.com/industry/risk-analyst/)
- Related: [Risk Analyst](https://learn.tradelabsai.com/industry/risk-analyst/): Risk analysts measure, report and control market, credit and operational risk at trading firms. Learn the daily work, key tools, skills and the risk career path.
- Related: [Clearing, Settlement and Custody](https://learn.tradelabsai.com/industry/clearing-settlement-and-custody/): After a trade, clearing confirms and guarantees it, settlement exchanges cash and securities and custody holds assets safely. Learn the process, T+1 and key players.
- Related: [Logging, Audit Trails and Incident Response](https://learn.tradelabsai.com/algo-trading/audit-trails/): An audit trail records every signal, order, change and fill so trading can be reconstructed later. Learn what to log, the regulatory rules and how it helps traders.
- Related: [Execution Reports and Trade Confirmations](https://learn.tradelabsai.com/orders/trade-confirmations/): After you trade, you receive order acknowledgments, execution reports and a trade confirmation. Learn what each one shows and how to use them to check your fills.
- Related: [Fund Accounting and NAV](https://learn.tradelabsai.com/industry/fund-accounting-and-nav/): Net asset value is a fund's assets minus liabilities, divided by shares. Learn how NAV is calculated, how assets are valued and how errors happen.
- Related: [Record Keeping for Traders](https://learn.tradelabsai.com/industry/record-keeping-for-traders/): Good records protect traders at tax time, in disputes and in self review. Learn what to record for every trade, how long to keep records and simple systems.