Transaction Processing Basics

Learning objectives

By the end of this chapter, you should be able to:

• Explain the purpose of key source documents used to initiate, authorise, evidence, and record transactions (including purchase orders, goods received notes, and invoices).
• Apply document-matching controls to validate transactions in the purchase-to-pay and order-to-cash cycles.
• Apply cut-off procedures at period end and deal appropriately with missing-document situations while keeping records complete and accurate.
• Maintain a clear audit trail by cross-referencing ledger entries to supporting evidence and resolving gaps promptly.
• Assess how segregation of duties and authorisation points reduce error and fraud risk.
• Describe how system and workflow controls improve the integrity of transaction processing.

Overview & key concepts

Transaction processing is the practical “engine room” of accounting. Businesses generate large volumes of transactions, and financial statements are only as reliable as the underlying records.

Two process cycles appear throughout this chapter:

• Purchase-to-pay: from identifying a need to buy, through ordering and receiving, to recording the liability and paying the supplier.
• Order-to-cash: from receiving and approving a customer order, through supplying and invoicing, to collecting cash.

A strong transaction-processing process has four recurring themes:

• Evidence: every recorded entry should be supported by appropriate documentation.
• Matching: documents that describe the same event should agree (what was ordered, received, and invoiced; what was approved, supplied, and billed).
• Timing (cut-off): transactions must be recorded in the correct accounting period.
• Controls: responsibilities, approvals, and system rules reduce mistakes and deliberate manipulation.

A crucial point:

• Documents do not change the accounting equation by themselves.
• A purchase order or customer order is evidence of intention and authorisation, but it is not normally a journal entry. The accounting records change when the underlying transaction occurs (for example, goods are received, an invoice is issued, cash is paid/received).

Core source documents

Source documents are the primary evidence that a transaction occurred and that it was authorised. They also provide the detail needed to record the correct amount in the correct accounts.

Purchase-to-pay (buying and paying)

Common documents include:

• Purchase requisition: internal request to buy goods/services.
• Authorised purchase order (PO): formal order placed with a supplier, confirming quantities, prices, and terms.
• Goods received note (GRN): evidence of receipt (what arrived, when, and in what quantity/condition).
• Supplier invoice: request for payment that supports measurement and posting of the liability.
• Supplier statement: summary of invoices/credits and payments (useful for reconciliation).
• Payment documentation: payment run listing, remittance advice, bank confirmation.

Key accounting link:

• For goods, receipt (control/benefit obtained) is usually the recognition point; for services, recognition follows evidence that the service has been received/consumed or completed, with the invoice supporting measurement.

Order-to-cash (selling and collecting)

Common documents include:

• Customer order / sales order: request to supply goods/services, often supported by credit approval.
• Dispatch note(sometimes called a delivery note): evidence goods were supplied.
• Sales invoice: billing document that supports measurement and is often the system trigger for recording a receivable and revenue.
• Credit note: evidence of a valid reduction in the amount owed (returns, pricing corrections, allowances).
• Customer remittance / bank receipt: evidence of settlement.

Key accounting link:

• Asales invoiceoften creates the receivable in the system, and may also be the system trigger for revenue posting. However,revenue recognition should follow the underlying revenue policy(for example, when control transfers or the performance obligation is satisfied), with dispatch documentation acting as evidence that this point has been reached.Receivables arise when the right to consideration becomes unconditional; systems often record this at invoicing.

Document matching controls

Document matching as a “validity test”

Matching is a practical way to answer two exam-critical questions before you post or pay:

1. Was the transaction properly approved?
2. Did the transaction actually happen as described?

Purchases: matching the story of the transaction

In a purchase, different documents describe the same event from different angles:

• thePOshows what the business agreed to buy and the terms it accepted,
• theGRNshows what arrived (and when),
• thesupplier invoiceshows what the supplier is asking to be paid.

A robust process checks that these documents refer to the same supplier and items, and that key details are consistent. Minor differences can be allowed, but only within pre-set limits and with a clear reason recorded.

Think “what could go wrong?” and match the control to the risk:

• paying for items that never arrived,
• being charged the wrong price or quantity,
• paying the same invoice twice,
• processing a purchase that was never properly authorised.

Sales: ensuring supply and billing line up

On the sales side, the focus is to ensure that what was supplied and what was billed agree with authorised prices and credit decisions. A common check is that:

• anapproved customer order(including any credit decision),
• adispatch note, and
• thesales invoice

all align in terms of customer, quantities, prices, and terms.

Cut-off and missing-document scenarios

Cut-off is about recording transactions in the correct period. Period-end errors often arise because documents arrive in a different sequence.

Purchases cut-off (GRNs unmatched to invoices)

A common period-end control is a report of received-but-not-invoiced items. If goods have been received by the reporting date, the business may need to recognise:

• theasset(inventory) orexpense, and
• aliability(a goods-received-not-invoiced balance),

even if the supplier invoice arrives later.

Terminology note: a goods-received-not-invoiced balance is a specific type of accrual used for goods receipts pending invoice; accruals for services are often estimated using time-based or service-completion evidence rather than GRNs.

Sales cut-off (supplied-but-not-invoiced items)

A typical control is a report of supplied-but-not-invoiced items. If goods/services were supplied by period end, revenue may need to be recorded in that period if the entity’s revenue policy indicates that control has transferred (or the performance obligation has been satisfied). Dispatch notes are commonly used as evidence of supply, but the recognition point is driven by the policy, not the paperwork.

Missing documents

If a key document is missing:

• donotignore the transaction if there is reliable alternative evidence (for example, GRN plus PO for goods received),
• record an appropriateprovisional postingusing best available information,
• obtain replacement evidence promptly and resolve the record.

To prevent provisional entries becoming permanent, any overrides should be authorised, logged, time-limited, and followed up through an exception report until cleared.

Audit trail discipline

An audit trail allows a reader to follow figures in the accounts back to the underlying evidence.

Good audit trail habits include:

• every posting references a document number (invoice number, GRN number, receipt number),
• documents are filed in a consistent structure (physical or electronic),
• changes to master data (supplier bank details, customer limits, prices) are logged and reviewed,
• exceptions (overrides, unmatched items, manual journals) are monitored and explained.

If a ledger entry cannot be traced to evidence, it should be treated as a red flag and investigated promptly.

Segregation of duties and authorisation points

Segregation of duties: separating “create, check, and control cash”

Internal control is stronger when the same person cannot both set something up, confirm it, and benefit from it. In transaction processing, that usually means splitting responsibilities across:

• Initiation(requesting or setting up the transaction),
• Approval(independent sign-off),
• Recording(posting to the ledger),
• Custody(handling cash or releasing bank payments).

Examples:

• In purchases, the person who approves the order should not be the person who authorises the payment run.
• Bank reconciliations should be performed by someone who cannot create or release payments.
• Changes to supplier payment details should be reviewed independently and ideally require extra confirmation before the next payment is released.

Authorisation points

Authorisation points are the “gates” where exceptions must be justified—such as approving unusual discounts, overriding matching tolerances, or releasing high-value payments. These controls deter manipulation and create a clear accountability trail.

System and workflow controls

Modern accounting systems reduce error by building controls into workflows. Common system controls include:

• role-based access (users can only perform appropriate tasks),
• mandatory fields and document attachments before approval,
• duplicate invoice detection (supplier, invoice number, amount),
• tolerance rules for matching (quantity/price limits),
• controlled payment runs (review + approval before release),
• audit logs for changes and overrides,
• exception reporting for unmatched items and manual journals.

System controls are most effective when they are monitored: exception reports should be reviewed, and overrides should be justified.

Core theory and frameworks

Recognition: when to record

Record a transaction when it meets the relevant accounting definition (for example, an asset, liability, income, or expense) and the recognition point has been reached under the entity’s policies.

In plain terms, recognition usually requires that:

• the underlying event has happened (it is not just an intention), and
• the amount can be measured with sufficient reliability.

For revenue, the key question is whether the entity has fulfilled what it promised to the customer (commonly assessed through control transfer / performance obligation satisfaction). Invoicing and dispatch documentation often provide evidence and measurement, but they are not the underlying principle.

Measurement: what amount to record

Amounts are recorded based on the agreed transaction value, adjusted for items such as:

• trade discounts and authorised price reductions,
• sales taxes collected on behalf of tax authorities (recorded as a liability, not income),
• returns/credit notes,
• settlement discounts, based on the entity’s policy (for example, recorded when taken, or reflected earlier if expected).

Double-entry: keeping the equation balanced

Each posting has two sides that must total the same amount, so the accounting equation stays in balance. A practical way to remember the direction is:

• Resources owned or controlled (assets) and costs (expenses) generally grow on the debit side.
• Obligations (liabilities), owner funding/retained results (equity), and income generally grow on the credit side.

If one balance increases, the matching entry either increases another balance or reduces a different one—so the totals still reconcile.

This keeps the accounting equation balanced:

Assets = Liabilities + Equity

Cash vs credit transactions

• Credit transaction: creates a receivable or payable. Cash moves later.
• Cash transaction: cash moves immediately (and there is no receivable/payable unless there is a timing difference).

Inventory and cost of sales

For goods-based businesses, sales typically require two sets of entries:

1. Recognise the sale (revenue and receivable/cash, plus sales tax if applicable).
2. Recognise the cost (cost of sales and reduction of inventory).

The second entry depends on inventory records and the costing method used.

Worked example

Narrative scenario

ABC Corporation is a medium-sized manufacturing company that processes a high volume of transactions. During December, the following events occurred:

1. Raw materials costing$50,000were purchased on credit. A purchase order was raised and goods were received (GRN prepared).
2. The supplier invoice for the$50,000raw materials was received and matched to the PO and GRN.
3. Finished goods were sold on credit for$100,000(selling price before sales tax). A sales order was authorised and a dispatch note was issued.
4. A sales invoice was issued for the finished goods.
5. Operating expenses of$20,000were paid in cash, supported by valid receipts.
6. Sales tax applies at anassumed rate of 20%on the sale.
7. The customer is offered an8.5% early settlement discounton the selling price (before sales tax), if payment is made within the discount period.
8. At month end, goods costing$5,000were received with a GRN, but the supplier invoice had not yet arrived.
9. Month-end procedures included reconciling unmatched GRNs and supplied-but-not-invoiced items, and reviewing overrides/authorisations.

Required

• Compute total sales revenue and cost of sales for December.
• Prepare journal entries for the purchase and sale transactions (including sales tax).
• Reconcile the accounts payable and accounts receivable balances at month end.
• Calculate the sales tax and early settlement discount amounts.
• Record the accrual for goods received but not yet invoiced.
• Explain how segregation of duties and authorisation points reduce risk in transaction processing.
• Explain how system controls help prevent errors and fraud.

Solution

1) Compute total sales revenue and cost of sales

Sales revenue (before sales tax): $100,000

Cost of sales: determined from inventory records for the finished goods supplied in December (not from the raw-material purchase value).

Assume the inventory records show:

• Cost of finished goods dispatched in December = $50,000
• (This is the cost of the items sold, and it is not necessarily equal to the raw materials purchased during the month.)

So:

• Cost of sales:$50,000

2) Journal entries for purchase and sale transactions

(a) Purchase of raw materials on credit (on receipt / invoice matched)

When the raw materials are received and the invoice is matched:

• Dr Inventory (raw materials)$50,000
• Cr Trade payables$50,000

(A purchase order itself does not create a journal entry.)

(b) Sale of finished goods on credit (including sales tax)

Sales tax collected is not income; it is a liability payable to the tax authority.

Sales tax = $100,000 × 20% = $20,000
Total invoice amount = $100,000 + $20,000 = $120,000

Journal entry on invoicing:

• Dr Trade receivables$120,000
• Cr Revenue$100,000
• Cr Sales tax payable$20,000

(In many systems, invoicing is the posting trigger; however, recognition follows the entity’s revenue policy. Receivables arise when the right to consideration becomes unconditional, which systems commonly capture at invoicing.)

(c) Record the cost of the finished goods sold

Based on the inventory record cost:

• Dr Cost of sales$50,000
• Cr Inventory (finished goods)$50,000

(d) Payment of operating expenses in cash

• Dr Operating expenses$20,000
• Cr Cash / bank$20,000

3) Reconcile accounts payable and accounts receivable (month end)

Assume opening balances were zero and no payments/receipts were made by 31 December.

Trade payables

• Supplier invoice matched for raw materials:$50,000
• Month-end goods-received-not-invoiced balance: shown separately as an accrual (see section 5)

So:

• Trade payables (closing): $50,000

Trade receivables

• Sales invoice total (including sales tax):$120,000

So:

• Trade receivables (closing): $120,000

4) Calculate sales tax and discount amounts

Sales tax

Sales tax = $100,000 × 20% = $20,000

Early settlement discount (offered)

Discount is 8.5% of selling price (before sales tax):

Discount on revenue = $100,000 × 8.5% = $8,500

If the customer takes the discount and the tax base follows the consideration actually received, the sales tax would reduce as well:

Reduction in sales tax = $8,500 × 20% = $1,700

Total reduction in amount collected (if discount taken) = $8,500 + $1,700 = $10,200

Measurement note: a settlement discount affects the amount of consideration ultimately received. Depending on policy and materiality, it may be presented as a reduction of revenue or shown separately as a discount/finance-type line in internal reporting, but the key point is that it reduces the transaction consideration.

Tax note: whether output tax reduces depends on jurisdiction; this example assumes tax is calculated on consideration actually received.

5) Record the accrual for goods received but not yet invoiced ($5,000)

Goods were received before month end, so the business recognises the asset (inventory) and a liability (goods received not invoiced) even though the invoice is missing:

• Dr Inventory$5,000
• Cr Goods received not invoiced (liability)$5,000

This liability will be cleared when the supplier invoice arrives and is matched.

6) Impact of segregation of duties and authorisation points

Segregation of duties reduces both errors and deliberate fraud because key steps are performed by different individuals (or different system roles), such as:

• the person who approves purchases is not the same person who releases payments,
• bank reconciliations are performed independently of payment processing,
• supplier master data changes are reviewed separately from payment approval.

Authorisation points strengthen the process by ensuring that exceptions require approval and leave evidence, such as:

• independent credit approval before dispatch,
• approval and logging of discount overrides,
• approval thresholds for purchase orders and payment runs.

7) Role of system controls in preventing errors and fraud

System controls reduce risk by enforcing consistency and making exceptions visible. Examples include:

• restricting who can set up suppliers or amend bank details,
• requiring a matched PO/GRN/invoice before posting or paying,
• blocking duplicate invoices with the same supplier and invoice number,
• logging overrides and manual journals for review,
• producing exception reports for unmatched GRNs and supplied-but-not-invoiced items.

Well-configured system controls improve accuracy, speed, and traceability—provided exceptions are reviewed and acted upon.

Interpretation of the results

The entries show how transaction processing converts operational events into financial statement figures:

• Revenue is recorded at$100,000, while the$20,000sales tax is recorded as a liability rather than income.
• Trade receivables reflect the full invoice amount ($120,000) because the sale was on credit.
• Inventory and cost of sales are captured through a separate entry, ensuring profit is measured correctly.
• The month-end goods-received-not-invoiced balance ($5,000) prevents liabilities being understated simply because an invoice arrived late.

A common exam trap is treating documents like purchase orders as if they create accounting entries, or recording sales tax as revenue instead of a liability.

Common pitfalls and misunderstandings

• Posting from the wrong trigger: A common mistake is treating authorisation paperwork as if it were the transaction itself. For example, a purchase order approves a purchase, but it does not prove receipt or create a liability—posting should follow the event (receipt or service received) and reliable measurement.
• Paying before the evidence is complete: If an invoice is paid without checking it back to receipt evidence (or an approved exception), problems are often discovered only after cash has left the bank—duplicate invoices, incorrect quantities, or charges for items never received.
• Cut-off errors at period end:Failing to record goods received not invoiced can understate liabilities (and understate expenses if goods were consumed).
• Revenue anchored to paperwork:Dispatch notes and invoices provide evidence, but revenue recognition should follow the entity’s revenue policy (for example, control transfer / performance obligation satisfaction).
• Sales tax treated as income:Sales tax collected belongs to the tax authority and should be recorded as a liability.
• Missing the second entry for inventory sales:For goods, a sale usually requires both the revenue entry and the cost of sales entry.
• Confusing settlement discounts:Settlement discounts affect the measurement of consideration. The accounting timing depends on policy, and the tax impact depends on local rules.
• Unreconciled control accounts:If receivables/payables are not reconciled to underlying listings and statements, errors can accumulate unnoticed.
• Poor audit trail:Entries without document references or support create avoidable risk and can be difficult to correct later.
• Inadequate segregation of duties:Concentrating initiation, approval, recording, and payment with one person increases both fraud risk and accidental error.

Summary and further reading

Transaction processing is built on reliable evidence, disciplined matching, correct cut-off, and strong internal controls. Core documents (POs, GRNs, dispatch notes, invoices, receipts) support accurate recording, while reconciliations and audit trails ensure ledger balances can be verified.

For further study, focus on:

• double-entry logic and how it maintains the accounting equation,
• how to record credit vs cash transactions,
• common period-end adjustments (cut-off and goods received not invoiced),
• the difference between revenue and amounts collected on behalf of third parties (such as sales tax),
• how settlement discounts affect measurement and presentation.

FAQ

What is the purpose of matching controls in sales and purchases?

Matching checks that the transaction is both approved and genuine. On purchases it links ordering, receipt, and billing. On sales it links approval (including credit), supply evidence, and billing—helping prevent missed invoices, incorrect pricing, or unauthorised transactions.

What is the purpose of the three-way match?

It confirms that a purchase is valid and accurate by ensuring that the PO (authorisation), GRN (receipt), and supplier invoice (billing) agree. This reduces the risk of paying for goods not received, paying incorrect prices, or processing duplicate invoices.

How do cut-off procedures improve financial reporting?

They ensure transactions are recorded in the correct accounting period. Period-end controls (such as unmatched GRN reviews and supplied-but-not-invoiced reports) help prevent liabilities, expenses, revenue, or receivables being misstated.

Does dispatch automatically mean revenue should be recognised?

Not automatically. Dispatch documentation is often strong evidence of supply, but the recognition point depends on the entity’s revenue policy (for example, when control transfers or the performance obligation is satisfied).

How should goods received but not yet invoiced be recorded?

If goods are received before period end, recognise the inventory (or expense) and record a liability for goods received not invoiced. When the supplier invoice arrives, the liability is cleared through matching and posting.

What happens if a customer takes an early settlement discount?

The business collects less cash than the invoice total. Depending on policy and materiality, the discount may be presented as a reduction of revenue or shown separately, but it reduces transaction consideration. Any related sales tax adjustment depends on local tax rules; in this chapter’s example, tax reduces because it is assumed to be calculated on the amount actually received.

Summary (Recap)

This chapter explained how transaction processing converts day-to-day business activity into accurate accounting records. It covered the purpose of core source documents, how matching controls validate purchases and sales, and how cut-off procedures prevent period-end misstatements. It also emphasised audit trail discipline, segregation of duties, authorisation points, and system controls as practical safeguards against error and fraud. The worked example illustrated correct journal entries for purchases, credit sales including sales tax, operating expenses, and goods received not invoiced.

Glossary

Source documents
Primary evidence that supports a transaction and provides the detail needed to record it (for example, invoices, receipts, GRNs, dispatch notes).

Purchase-to-pay cycle
The process from requesting and approving a purchase, through ordering and receiving, to recording the liability and paying the supplier.

Order-to-cash cycle
The process from receiving and approving a customer order, through supplying and invoicing, to collecting cash.

Purchase order (PO)
An authorised order sent to a supplier confirming what is to be purchased and on what terms.

Goods received note (GRN)
Evidence that goods were received, including quantities and date of receipt.

Three-way match
A control that compares the PO, GRN, and supplier invoice to confirm the purchase is valid and accurate before posting/payment.

Cut-off
Recording transactions in the correct accounting period, especially around period end.

Goods received not invoiced (liability)
A liability recorded when goods have been received but the supplier invoice has not yet been processed; a goods-specific form of accrual.

Accrual (general)
A liability or adjustment recorded when costs or income relate to the current period but the related invoice or cash movement has not yet been recorded.

Audit trail
A clear path that links ledger entries to supporting evidence, enabling verification and investigation.

Segregation of duties
Dividing responsibilities so that one person cannot independently initiate, approve, record, and control settlement of the same transaction.

Role-based access
A system rule limiting what a user can do based on their assigned responsibilities.

Change logs
System records showing who changed key data, what changed, and when.

Duplicate invoice checks
Controls designed to prevent the same supplier invoice being processed more than once.

Controlled payment run
A structured payment process requiring review and approval before releasing payments.