A client sells more and more to private customers every month, revenue keeps climbing, and nobody in the business is tracking how much of it already counts toward the cash-register exemption threshold. That threshold is 20,000 PLN of turnover from sales to individuals who don't run a business, or to flat-rate farmers, in the previous tax year — and the accounting office is usually the first party positioned to notice a client approaching it.
This page walks through exactly how that threshold is calculated, what happens once it's crossed, and where the office's role ends and the tax advisor's decision begins.
What the cash-register exemption is and who it applies to
The subjective exemption from the obligation to use a cash register applies when turnover from sales to individuals who don't run a business, plus flat-rate farmers, did not exceed 20,000 PLN in the previous tax year (biznes.gov.pl, exemption from the cash-register obligation). This is the subjective exemption; separate object-based exemptions exist for specific kinds of sales, but that's a conversation for a tax advisor, not this article.
The key phrase is "individuals who don't run a business." That phrase also defines what does not count toward the threshold.
B2B sales are counted separately
Only sales to consumers and flat-rate farmers count toward the 20,000 PLN threshold. Sales to other businesses (B2B) are not part of that turnover — this follows directly from the exemption's own definition. In practice, a client who sells mostly to other companies, with occasional retail sales on the side, only needs to watch that second, smaller stream. An office that adds up the whole company turnover will either raise a false alarm or, worse, miss the real approach to the threshold.
The threshold scales with how long the business has operated
A business that wasn't operating for the full year doesn't get the full 20,000 PLN allowance — the amount is calculated proportionally to the period the business operated during that tax year. For a client who registered in, say, September, that works out to a noticeably lower threshold than the full 20,000 — the exact figure comes from the ratio of months operated to 12.
This is one of the more common mistakes in office practice: a new client mid-year gets treated as if they had the full annual limit, because nobody recalculated the proportion at the start of the engagement. One sentence in the first conversation with any new retail-facing client saves a surprise a few months later.
What happens after the threshold is crossed — not "immediately"
Crossing 20,000 PLN doesn't trigger a cash-register obligation the next day. The exemption expires after 2 months following the month in which the 20,000 PLN threshold was exceeded (biznes.gov.pl). If a client crosses the threshold in June, the cash register becomes mandatory from 1 September.
Those two months are real time to prepare calmly — choosing a device, registering it with the tax office, training whoever staffs the till — instead of an emergency purchase in the last week of August. The catch is that this time is only useful if someone noticed the crossing when it happened, not at year-end closing.
The 450 PLN NIP receipt, and why it's a separate topic from KSeF
Until 31 December 2026, invoices can still be issued through cash registers, including NIP receipts up to 450 PLN treated as simplified invoices, without an obligation to issue them in KSeF (KSeF — Consumers and individuals, FAQ). Both before and after 1 February 2026, issuing B2C invoices in KSeF remains voluntary.
That's useful context for a client who's just about to need a cash register: the register itself and a NIP receipt are not the same thing as mandatory KSeF invoicing for B2C sales. We cover KSeF invoicing integration separately in Invoicing Automation and KSeF: What Your System Must Be Able to Do — here we stay focused on what directly concerns the 20,000 PLN threshold.
What an accounting office doesn't decide for the client
The office sees the numbers before the client does, but the decision on whether and when a specific business must introduce a cash register belongs to the client's tax advisor, who knows the full picture — including any object-based exemptions that could change it. The office's job is to notice the approach to the threshold and flag it in time, not to make that call on its own.
It's worth writing this distinction into the office's working standard: "we flag the threshold — the advisor decides with the client." That protects the office from being blamed for a wrong legal call, while still holding it to the duty of informing the client on time.
In practice, a short note to the client when turnover approaches the threshold works well: just the fact of getting close, without a legal verdict of "you must buy one" or "you don't." A client with that note arrives at the tax advisor already prepared, instead of finding out about the issue after the fact, at year-end settlement.
Since the office is already processing this client's sales data to count the turnover, it's worth knowing where that data physically ends up and who has access to it — we cover that in Automation and GDPR: where your customer data physically ends up.
Tracking a client's turnover without a spreadsheet kept on the side
A classic spreadsheet, updated whenever someone remembers to, works only for as long as someone remembers to open it. For an office handling a dozen or several dozen businesses, that doesn't scale: Aura Integrations connect sales data from a till, a shop, or a booking system into one stream, so cumulative turnover adds itself up instead of being copied by hand between systems. On choosing the numbers an office owner actually looks at, see Reporting automation: how to set up numbers that the owner actually looks at.
The common mistake: checking once a quarter
Checking a client's turnover once a quarter sounds reasonable until you count how much delay that adds in practice. A client who crosses the threshold in the first month of a quarter, only noticed at the quarterly review, loses part of the two-month preparation window before anyone even starts acting. A more frequent look — weekly, or automatic on every new transaction — leaves more room for a calm response.
The problem scales with the number of clients an office handles. With five retail clients, a manual weekly check is doable. With fifty, someone eventually skips one business in a busy week — and that's usually the one that crosses the threshold unnoticed. Replacing the manual review with a counter that sums and flags the threshold on its own isn't a convenience; it's what keeps client count from becoming a source of risk.
A worked example with round numbers: finding the crossing month
The example below uses round, illustrative numbers — plug in your own client's figures to get a real answer.
Step by step: the running total
The same mechanism produces a different result for every client — a seasonal shop with uneven sales through the year will cross the threshold in a jump rather than an even pace, so its path through this illustrative example will look nothing like the one above.
What to do yourself: a checklist for the office
The 20,000 PLN threshold is one of several thresholds worth watching in a small business before automating anything — we cover the others in Where to start automation in a small business: four thresholds instead of general analysis.
- List clients who sell retail to individuals or flat-rate farmers.
- For each one, add up turnover from the start of the tax year, counting only B2C sales.
- For businesses started mid-year, recalculate the threshold proportionally to months of operation.
- Set an alert level at roughly 80% of the threshold — that leaves margin to react before it's crossed.
- Once a client crosses the threshold, record the crossing month and calculate the exemption's expiry date (crossing month plus two).
- Pass the information to the client and route the cash-register decision to their tax advisor.
What this looks like when a system manages it
Instead of a spreadsheet updated from memory, a client's sales data lands in one place, and the system tracks the running turnover on its own:
- 01sales data
- →02running counter
- →03alert at 80%
- →04a task on the office's calendar
Dashboards show the current state of every client on one screen, and AI Reports send a weekly summary, so nobody has to remember to open a panel. CRM and automations keep this data on the client's record instead of in a separate file, and Finance shows turnover in the same time unit as the rest of the business's numbers. The final decision on whether a cash register is required always stays with the client's tax advisor — the system's job is only to make sure nobody finds out about the threshold too late.
Frequently asked questions
Do sales to other businesses (B2B) count toward the 20,000 PLN threshold?
No. The threshold covers only turnover from sales to individuals who don't run a business, plus flat-rate farmers. Sales to other companies don't count toward that turnover.
Exactly when does a client lose the cash-register exemption after crossing the threshold?
The exemption expires after 2 months following the month in which the 20,000 PLN threshold was exceeded. Crossing it in June means the cash register becomes mandatory from 1 September.
How is the threshold calculated for a business started mid-year?
The 20,000 PLN threshold is calculated proportionally to the period the business operated during that tax year, not at the full amount from the registration date.
Does a NIP receipt up to 450 PLN replace a KSeF invoice?
Until 31 December 2026, invoices can still be issued through cash registers, including NIP receipts up to 450 PLN treated as simplified invoices, without an obligation to issue them in KSeF. B2C invoicing in KSeF stays voluntary throughout, both before and after 1 February 2026.
Who ultimately decides whether a client needs a cash register?
The client's tax advisor makes the final call, weighing in any object-based exemptions that might apply. The accounting office flags the approach to the threshold, but it doesn't replace that decision.
How often should an office check a client's turnover against the 20,000 PLN threshold?
The more often, the less risk of a late reaction — checking once a quarter leaves less of the two-month preparation window than tracking the running turnover weekly, or automatically with every new transaction.