1. What makes trading accounting its own problem
A trader's transaction is simple — buy goods, sell the same goods, book the margin — but the shape of the business makes the accounting distinctive. The transaction count is high and individual bill values are low, most sales are to unregistered walk-in customers rather than named businesses, the catalogue spans several GST rates at once, and money arrives in three forms — cash, UPI and card — that all have to be reconciled back to the sales they represent.
None of that is hard in isolation. It becomes hard because it repeats hundreds of times a day and has to be summarised, correctly, into a monthly return. The two decisions that shape everything else are which scheme you run under and how you handle a mixed-rate catalogue — so those come first.
2. The composition scheme decision
The single biggest structural choice a small trader makes under GST is whether to opt for the composition scheme under Section 10. It trades simplicity for the loss of input tax credit, and whether that trade is worth it depends entirely on the business.
Under composition, a trader with aggregate turnover within the notified limit (₹1.5 crore, lower for special-category states, and subject to change) pays tax at a flat 1% of turnover, files a simple quarterly statement (CMP-08) and an annual return, and is spared invoice-level reporting. In exchange, three hard restrictions apply: you cannot collect GST from customers, you cannot claim input tax credit on your purchases, and you cannot make inter-state outward supplies. A composition dealer issues a bill of supply, not a tax invoice, and must display that they are a composition taxable person.
| Composition scheme | Regular scheme | |
|---|---|---|
| Tax rate | Flat 1% of turnover (traders) | Item's GST rate, collected from customer |
| Input tax credit | Not available | Available on eligible purchases |
| Tax collected from customer | No — borne by the dealer | Yes — passed on |
| Inter-state outward sales | Not allowed | Allowed |
| Document issued | Bill of supply | Tax invoice |
| Returns | CMP-08 quarterly + annual | GSTR-1 and GSTR-3B, monthly or quarterly |
The restriction that most often forces the choice is the inter-state one: the moment a trader wants to sell across a state boundary, composition is off the table. Growth decides the scheme as much as arithmetic does.
3. A mixed-rate catalogue
Unlike a specialist manufacturer, a general retailer stocks goods across several GST slabs at once — nil, 5%, 12%, 18% and 28% items can all sit on the same shelf, and some carry cess on top. Every product has to be mapped to its correct rate and HSN code, because the rate is a property of the goods, not a setting for the shop.
This is where counter billing meets tax accuracy. A bill that applies one blanket rate to a mixed basket is wrong on most lines, and the error repeats on every similar sale. The only sustainable answer is that each item carries its rate and HSN in the catalogue, so the correct tax falls out of the sale automatically rather than being decided at the counter. For quick checks on a single price, a standalone calculator helps, but at volume the rate has to live with the product.
GST calculator — add or remove GST
4. HSN codes on invoices
HSN — the Harmonised System of Nomenclature — is the code that classifies each good, and GST requires it to be quoted on invoices and reported in returns. How many digits you must quote depends on turnover: broadly, businesses report at four digits up to a turnover threshold and at six digits above it, with the requirement having been tightened over successive years.
For a trader the practical burden is coverage, not difficulty: every SKU needs the right HSN once, and after that it is automatic. The businesses that struggle are the ones classifying items ad hoc at billing time; the ones that do not are those that fixed the HSN in the product master when the item was first stocked. Getting it wrong is not just a filing nuisance — the HSN drives the rate, so a mis-coded item is usually a mis-taxed item too.
5. Turning a day of counter sales into a return
A trader's return is where the volume problem is most visible. GSTR-1 does not ask a B2C retailer to report every walk-in bill by name. Business-to-business supplies are reported invoice by invoice, but business-to-consumer sales are reported in aggregate — summarised rate-wise, and state-wise for larger inter-state supplies — rather than customer by customer.
That aggregation is a relief, but it puts the weight on the summary being right. The rate-wise totals in the return have to reconcile to the day's actual sales across every rate slab, and GSTR-3B — the summary return through which tax is paid — has to agree with GSTR-1. A business that captures each sale at its correct rate produces those totals as a by-product; one that reconstructs them from a till roll at month end is doing arithmetic it does not need to, and getting it wrong in ways that are hard to trace back.
6. Input credit and stock, for a regular-scheme trader
A trader on the regular scheme lives or dies by input tax credit, because at thin trading margins the credit on purchases is a large part of what makes the numbers work. Credit can only be claimed on purchase invoices that appear in your auto-drafted GSTR-2B, so every purchase has to be matched against it every month, and every mismatch chased while the supplier still has reason to fix it.
For a fast-turnover business this reconciliation is not a year-end tidy-up; it is a monthly control, and the outer time limit for claiming a credit closes at 30 November following the financial year. The full mechanics — the four cumulative conditions, the GSTR-2B dependency, the 180-day payment rule and the blocked credits in Section 17(5) — are the same for a trader as for anyone else and are set out in the input tax credit guide.
Input Tax Credit: conditions, reversals and blocked credits
Alongside the tax question sits the plain commercial one: stock turnover. A retailer's cash is tied up in inventory, and the difference between a healthy business and a struggling one is often how fast that stock moves and how little of it is dead. Stock has to be valued and aged for the same reason the tax has to be reconciled — because in a thin-margin business the money is in the details.
7. Cash, UPI and card — reconciling what actually arrived
Trading is one of the few businesses that still handles significant cash alongside a stream of digital payments, and the reconciliation problem is real. The day's sales figure has to match the money that actually landed — cash in the drawer, UPI into the bank, card settlements net of charges — and gaps between the two are where both errors and leakage hide.
Digital payments make this easier to get right, because they leave a bank trail, but only if that trail is reconciled against sales rather than assumed to agree. Matching daily takings to bank credits is the control that turns a pile of receipts into books you can trust, and it is the point at which a trading business either has a grip on its cash or does not.
8. A monthly discipline for a trading business
As with the other trades, almost everything above reduces to a set of habits. A trader that keeps to them rarely has a GST problem — and, just as important, always knows where the money is.
- Settle the scheme question on your own numbers — composition versus regular is an arithmetic decision about margin, purchases and whether you sell inter-state, not a rule of thumb.
- Fix every SKU's rate and HSN in the product master when it is first stocked, so counter billing is correct by default.
- Capture each sale at its correct rate so GSTR-1's rate-wise B2C totals fall out as a by-product, and keep GSTR-3B agreeing with GSTR-1.
- Reconcile purchases against GSTR-2B every month (regular scheme), chasing mismatches before the supplier's incentive to fix them fades.
- Value and age stock so dead inventory is visible and cash is not silently trapped on the shelves.
- Reconcile daily takings to the bank — cash, UPI and card — so the sales figure and the money agree.
- Watch the ₹1.5 crore composition ceiling and the registration threshold as turnover grows, so a scheme change is planned rather than triggered by a notice.
9. Where software should carry the load
None of this is difficult. It is hard because it is high-volume and repetitive, and because a small error made hundreds of times a day becomes a large one by month end. That is exactly the kind of work software exists to absorb.
Finkitaabh keeps each product's GST rate and HSN in the catalogue, so a mixed-rate basket is billed correctly at the counter and the rate-wise totals that GSTR-1 needs are produced as a by-product of the sales themselves rather than reconstructed from a till roll. GSTR-1 and GSTR-3B are generated from those posted sales in agreement with each other, and B2C sales are aggregated the way the return expects while B2B invoices are reported in full.
On the buying side, purchases reconcile against GSTR-2B monthly; stock is valued and aged so dead inventory shows; and daily takings across cash, UPI and card reconcile to the bank. The billing, the return and the cash position stop being three separate exercises and become one set of books.