Online shop accounting differs from handling a typical service firm above all in scale: hundreds of small orders, several payment channels, returns, platform commissions and often sales to other EU countries. The taxes are the same, but what becomes crucial is accurate reconciliation of sales against inflows, inventory settlement and proper documentation of every transaction. Below we describe how to organise an online shop's bookkeeping in practice so that the books match reality.
Form of activity and type of records
A shop owner acting as a natural person usually keeps the KPiR (tax book of revenue and expenditure) on the tax scale or flat tax (podatek liniowy), or the revenue register under ryczałt (lump-sum tax on recorded revenue), where trade is taxed at 3%. Full books of account are mandatory for sp. z o.o. (limited liability companies), joint-stock companies and limited partnerships regardless of turnover, and for natural persons as well as civil-law partnerships, general partnerships of natural persons and professional partnerships — after net revenue of EUR 2.5 million is exceeded in the previous financial year. Many shops voluntarily switch to full accounting because it gives better control over stock, margin and settlements.
The choice of taxation form is worth basing on margin. In trade in goods, purchase costs are high, so ryczałt on revenue is not always worthwhile, even at a low rate.
Documenting sales
Three types of sales document operate in parallel in an online shop:
- invoices for companies — from 2026 issued in KSeF; the obligation covered most taxpayers from 1 April 2026, and the smallest (sales up to PLN 10,000 per month) from 1 January 2027;
- cash-register receipts for consumers — when sales to private individuals exceed PLN 20,000 per year or when a given item does not qualify for the exemption;
- record of receipt-free sales — summaries of orders paid by transfer or through a payment gateway, if the shop uses the cash-register exemption.
The conditions for the cash-register exemption in mail-order sales are detailed and depend on, among other things, the method of payment and the type of goods, so it is worth checking them before starting — they are described in the article on who needs a cash register.
Reconciling inflows from payment gateways and platforms
The most common problem in shops is the gap between sales in the shop system and inflows to the bank account. The payment operator transfers money in bulk after deducting commission, and the sales platform does so after deducting listing and advertising fees. In accounting terms, you therefore need to:
- collect monthly settlement reports from each operator and platform;
- match inflows to specific orders and sales documents;
- recognise revenue at the gross order amount, and commission as a separate cost on the basis of the operator's invoice;
- explain differences: unpaid orders, chargebacks, currency conversions.
In sales in foreign currencies, revenue and costs are converted at NBP rates, which gives rise to exchange differences — it is worth settling them on an ongoing basis rather than only at year-end.
Returns, complaints and corrections
A consumer who bought goods online may withdraw from the contract within 14 days without stating a reason. The entrepreneur has 14 days to reply to a complaint — no reply means the complaint is deemed accepted. From the accounting point of view, a return means:
- for an invoice — a corrective invoice (in KSeF);
- for a receipt — an entry in the register of returns and complaints kept alongside the cash register;
- for receipt-free sales — a correction in the sales summary, linked to proof that the money has been refunded.
Every return should leave a trail: the customer's request, confirmation that the goods have been received back and a return transfer.
Goods, stock and physical inventory
Under the KPiR, the purchase of goods is a cost on the date it is incurred, but income is adjusted for the change in stock levels. The physical inventory is therefore drawn up on the date the business starts, on 1 January (unless done on 31 December) and at the end of each tax year. In full accounting, stock can be kept on an ongoing basis, which makes it easier to calculate the margin on individual products.
A shop's costs also include shipping, packaging, commissions, online advertising, the shop-software subscription and warehousing services. Invoices from foreign suppliers of digital services usually require settling the import of services in VAT.
VAT on sales to EU consumers
As long as the total annual value of sales to consumers from other EU states does not exceed EUR 10,000 (PLN 42,000), the shop applies Polish VAT. Once the threshold is exceeded, VAT of the buyer's country must be charged — most conveniently through the OSS procedure, described in the article on the VAT OSS procedure. The turnover-based VAT exemption limit in Poland in 2026 is PLN 240,000, but mail-order sales of certain goods exclude this exemption regardless of turnover.
Example of a monthly close
An accessories shop sells through its own website and one platform. Every month the accountant receives: an order report from the shop, reports from two payment operators, a settlement from the platform, a cash-register report, purchase invoices from KSeF and a bank statement. After reconciling inflows, it turns out that 3 orders are still awaiting payment and 5 have been returned. Only after these corrections are revenue, VAT for JPK_V7 (filed by the 25th day of the following month) and the income-tax advance determined.
How Good Balance can help
We provide full accounting for online shops: we reconcile inflows from operators and platforms, settle stock, returns, OSS and exchange differences. We also help put VAT invoicing in KSeF in order so that sales documents fit the books from the start.