GST Invoices, Batch and Expiry Records: Card Reconciliation for Medical Stores

GST Invoices, Batch and Expiry Records: Card Reconciliation for Medical Stores

Published: 24 October 2026

Category: how-to-guides | cardbuzz

Tags: GST invoices, batch records, expiry records, card reconciliation, pharmacy accounting, medical store

A pharmacy's day ends with three things that must agree: the invoices it issued, the stock it sold, and the card money it received. GST invoices record what was sold and the tax on it. Batch and expiry records record which physical stock left the shelf. Card settlements record what the payment provider actually paid. When all three reconcile, the store's accounts are sound. When they do not, the gap usually shows up at the worst moment — a tax filing, a stock audit, or a payment dispute.

This article explains how the three records fit together, and how a medical store can keep card reconciliation aligned with its GST and stock records.

GST Invoices: What the Bill Must Carry

A GST invoice from a pharmacy is more than a receipt. It is a tax document, and it should carry the details the tax system and the customer both need:

• Itemised lines. Each item sold, with quantity, rate and tax treatment, so the invoice can be checked line by line.
• Tax breakup. The applicable tax components shown separately, so the customer and the accountant can see how the total is composed.
• Buyer details where required. For business or institutional buyers, the details needed for their own tax records.
• Invoice numbering. Sequential, gap-free invoice numbers, so missing or duplicated invoices are immediately visible.
• Corrections, not deletions. A wrong invoice should be corrected through a proper credit note or revised document, not quietly deleted or overwritten. Deleted invoices break the sequence and the audit trail.

The invoice is the anchor document: stock records and card settlements should both be reconcilable back to it.

Batch and Expiry Records: Which Stock Left the Shelf

Medicines are not fungible the way most retail goods are. Two packs of the same product from different batches are different stock, with different expiry dates, and the store's records should know which batch each sale drew from:

• Batch tracking at sale. Where the system supports it, each sale should be linked to the batch it was drawn from, so the store knows exactly which physical stock was sold.
• Expiry discipline. Stock should be sold on a first-expiry-first-out basis, so the earliest-expiring stock leaves first and expiry losses are minimised.
• Expiry records. Expired or damaged stock should be recorded as such, with quantity, batch and reason, and removed from saleable stock through a documented process — not quietly written off.
• Recall readiness. If a batch is ever recalled, the store must be able to identify which customers received that batch. That is only possible if sales were linked to batches in the first place.
• Stock counts. Periodic physical counts should be matched against the system's stock, and differences investigated rather than adjusted away silently.

Batch and expiry records are often treated as a warehouse chore. In a pharmacy, they are a patient-safety and compliance record, and they belong in the same discipline as invoicing.

Card Reconciliation: Matching Money to Invoices

Card reconciliation is the process of matching what the payment provider settled against what the store invoiced. Done properly, it has a clear shape:

• Daily settlement matching. Each day's card settlements should be matched against the day's card-paid invoices, transaction by transaction, not merely in total.
• Net, not gross. Settlements arrive net of the card fee, so the reconciliation must account for the fee deduction — the settled amount will be less than the invoiced card total, by the fee.
• Timing differences. Settlements may arrive a day or more after the sale. The reconciliation should distinguish "settled" from "pending settlement", so a timing gap is not mistaken for a shortfall.
• Voids, refunds and chargebacks. A voided transaction, a refund or a disputed charge changes the settlement picture. Each should be recorded against the original invoice and transaction, so the reconciliation explains itself.
• Mixed payment invoices. An invoice paid partly by card and partly by another mode should reconcile in parts — the card portion against the settlement, the rest against its own payment record.

A store that reconciles only to the day's total will balance its cash while missing the transaction-level errors that matter: a settlement for the wrong amount, a missing settlement, or a refund recorded against the wrong invoice.

Bringing the Three Records Together

The real discipline is not any single record, but the linkage between them. A single sale should be traceable in all three dimensions:

• From invoice to stock. The invoice's line items should correspond to stock drawn from identified batches, so the store can answer "which batch did this invoice sell?"
• From invoice to payment. The invoice's card portion should correspond to a settlement line, so the store can answer "was this invoice's card payment received, and when?"
• From payment to stock. The settlement, through the invoice, should correspond to stock that actually left the shelf — a card payment with no matching invoice and no matching stock movement is a red flag.
• Exception reporting. The system — or the daily routine — should surface exceptions: invoices without matching settlements, settlements without matching invoices, stock movements without invoices, and invoices with stock drawn from expired batches.

This three-way linkage is what turns routine bookkeeping into a control system. When a question arises — from a customer, an accountant, a tax officer or a distributor — the answer is a short trace through three linked records, not a reconstruction from memory.

Common Reconciliation Failures

Several familiar failures break the three-way linkage:

• Invoicing after payment. Taking a card payment before issuing the invoice, and then invoicing from memory, creates invoices that do not match the payment amount or the stock drawn.
• Bulk invoicing. Recording a day's sales as a single lump invoice destroys the link to individual batches and individual card transactions.
• Ignoring the fee. Reconciling settlements to gross invoice totals without accounting for the card fee produces a permanent, unexplained shortfall that staff learn to ignore — which then hides real shortfalls.
• Refunds without linkage. Processing a card refund without linking it to the original invoice and batch leaves the invoice showing a sale that was reversed and stock records that do not reflect a return.
• Expiry write-offs without records. Removing expired stock without a documented record breaks the stock-to-invoice chain and hides the true cost of expiry.
• Month-end-only reconciliation. Reconciling once a month turns small daily errors into a large, untraceable mess. Daily reconciliation catches errors while the day's staff still remember them.

A Practical Daily Routine

A workable daily routine for a medical store need not be elaborate:

• Close the day's invoices. Confirm the day's invoice sequence is complete, with no gaps or duplicates.
• Match card settlements. Match each settlement line to its invoices, accounting for the card fee and for any voids or refunds.
• Check batch movements. Confirm the day's stock movements correspond to the day's invoices, and flag any movement without an invoice.
• Log exceptions. Record any mismatch with its cause and resolution, rather than adjusting figures silently.
• File together. Keep the day's invoices, settlement statement and stock movement summary filed together, so a later query has one place to start.

Done daily, this routine takes minutes. Done monthly, it takes days and still leaves gaps.

The Bottom Line for Medical Stores

GST invoices, batch and expiry records, and card settlements are three views of the same day's trading, and they must agree. Invoice every sale properly, link sales to batches, reconcile card settlements transaction by transaction accounting for the fee, and investigate exceptions daily rather than at month-end. The reward is not just cleaner accounts — it is the ability to answer any question about any sale, any batch and any payment, quickly and from records rather than from memory. That is the foundation a pharmacy's compliance, and its customers' trust, rests on.