Invoices for Allegro orders can be issued and sent without you clicking anything - all of automatic invoicing for Allegro orders comes down to one condition: one place that pulls the orders and talks to your accounting program. Allegro is Poland’s dominant marketplace, and integrating it with an accounting system (Fakturownia, iFirma, wFirma, inFakt, Optima or Subiekt are the common Polish ones) always works the same way: the system pulls the order data from Allegro (buyer, line items, amounts, delivery method), turns it into a sales document and sends the finished file back to the buyer. Your role ends at setting the rules: when the document should be created, which numbering series to use, and what should happen when the buyer supplies a VAT number.
This piece shows how to build that flow from scratch, what to choose at 20 orders a month versus 2,000, and where this automation most often falls over.
Automatic invoicing for Allegro orders - how it works in practice
Automatic invoicing rests on an API connection: Allegro exposes order data and the accounting program receives it. You authorise the connection once, and after that the same loop repeats on every order: pull the paid order, check for an invoice request and a VAT number, issue the document in the chosen series, upload the PDF onto the Allegro order and email it.
In practice I see three routes, differing not in price but in how much beyond invoices you want handled:
| Route | For whom | What it covers beyond invoices |
|---|---|---|
| Accounting program connected directly to Allegro | Selling on Allegro only, one warehouse, up to a few hundred orders a month | Nothing - documents and bookkeeping only |
| An order manager (e.g. Baselinker) in the middle | Several sales channels at once, parcels, couriers | Orders, labels, stock, statuses, messages |
| A custom integration over the Allegro API | An unusual process, an ERP, B2B sales, high volume | Exactly what you design |
An invoicing program with an Allegro integration: what to compare
Check these points in each candidate - Fakturownia, iFirma and order managers handle them differently:
- the moment of issue, settable as a rule
- VAT number recognition and named consumer invoices
- uploading the finished PDF back onto the Allegro order
- KSeF with queueing and retries
- credit notes and returns linked to the original
- a separate numbering series for the Allegro channel
- delivery cost as a separate line with the right rate
A human then handles only exceptions, off-pattern credit notes and the weekly check that documents match paid orders - the rest runs itself. If that flow has to cover your online store too, read the own store versus marketplace comparison first.
When the document should be created
The moment of issue is the most important setting in the whole integration, because it decides how many credit notes you will write. As standard the document is created after the order is paid, not after it is placed - unpaid orders can fall apart, and an invoice for a collapsed order means a credit note.
Typical events a rule can be built on:
- Order paid - the safest default for prepaid mail-order sales
- Order shipped - handy when you cancel some orders before shipping for lack of stock
- Cash on delivery - the document after the parcel is dispatched, because payment comes later
- Manually, on request - for rare exceptions, never as the main mode
Plus one housekeeping rule: one numbering series for the Allegro channel. When Allegro invoices go into the same series as invoices issued by hand in the office, sooner or later you get a gap or a duplicate number - and that is a conversation with your bookkeeper, not with a developer.
Invoice, receipt or nothing - who gets what
The principle is simple: a company with a VAT number gets an invoice, a private individual gets a sales document matching your record-keeping form, and the integration should work that out by itself. Allegro passes information in the order data on whether the buyer wants an invoice and whether they gave a VAT number - and that field is what the whole automation rests on.
Three situations that always have to be handled:
- Business buyer, VAT number supplied - an invoice to the company’s details, full accounting flow
- Private buyer who wants an invoice - a named invoice, no VAT number
- Private buyer who ticked nothing - a document matching your obligations: a till receipt or a simplified invoice, depending on whether you are required to use a fiscal cash register
That third case causes most of the mistakes. If you have a fiscal cash register or printer, the document flow has to account for it - I set that out in the piece on receipts, fiscal printers and JPK reporting in a store.
How the document reaches the buyer
The buyer should get the invoice in two places at once: attached to the order on Allegro and by email. Allegro has a slot in the order for a sales document - the integration uploads the PDF there automatically, so the buyer sees it in their account and stops sending “please send an invoice” messages.
Set the email up sensibly: the document as a PDF attachment, the Allegro order number and the invoice number in the body, sender on your own domain. That is not cosmetics - emails sent from a random address land in spam, and then the automation formally works while the buyer still gets nothing.
KSeF and selling on Allegro
Poland’s National e-Invoice System (KSeF) is already in force: it covered the largest taxpayers from February 2026 and everyone else from April 2026. For Allegro sales that means invoices issued to businesses pass through KSeF, the system assigns them an identifier, and the document the buyer receives is only a visualisation of that e-invoice.
What that changes in practice:
| Situation | What happens to the document |
|---|---|
| Invoice to a business (VAT number) | Goes to KSeF, the buyer receives a PDF visualisation |
| Named invoice to a consumer | Broadly outside the KSeF flow - the buyer receives the document from you |
| Credit note on a B2B invoice | Also through KSeF, linked to the original document |
| An outage on the system side | The accounting program queues it and sends once connectivity returns |
The key point when choosing a tool: the accounting program should handle KSeF for you, including queueing and retrying. What that looks like in practice I described in the piece on connecting your accounting program to KSeF, and for sellers working through an order manager - in the one on issuing invoices from Baselinker in the KSeF flow.
What breaks most often
Invoice automation rarely breaks, but always in the same places. Below are the symptoms I see when taking over such setups:
| Symptom | Usual cause | What to do |
|---|---|---|
| Some orders with no invoice | The Allegro connection authorisation expired | Renew access and set an expiry notification |
| Two invoices for one order | Two systems issuing in parallel | Leave one source of documents, disable the rest |
| Wrong VAT rate on a line | Missing data on the product at source | Fill in the rates at source, not on the document |
| The buyer did not get the email | Sending from the wrong domain, no SPF and DKIM | Fix the outgoing mail configuration |
| Delivery cost missing | The shipping line is not mapped | Add shipping as a separate line with the right rate |
| No orders arriving at all | The Allegro download broke | Diagnose the connection - I set that out in the piece on orders that do not reach Baselinker |
One thing worth watching from day one: the counter. Once a week, compare the number of paid orders with the number of documents issued. Three minutes, and it catches every silent failure before month-end.
What it costs and what to choose
Off-the-shelf integrations are cheap; custom ones cost what a project costs. Accounting programs and order managers bill monthly based on document or order counts - usually tens of zloty at low sales volume, rising with volume. Their price lists change several times a year, so check the exact figures at the source on the day you decide.
The recommendation I give most often:
- Selling on Allegro only, up to a few hundred orders a month - accounting program connected directly. Fewest moving parts
- Selling on Allegro and in your own store - an order manager as the single source of documents, so numbering and stock live in one place
- You have an ERP, B2B sales, unusual discounts or your own process - a bespoke integration, because off-the-shelf tools would have to be worked around anyway
That third option is a normal development project. With me those rollouts go as a quote up front, fixed-bid, usually in the 5,000-10,000 PLN net range - depending on how many systems have to be joined and how unusual the document rules are. If you sell on other platforms too, it pays to look straight away at connecting a marketplace to PrestaShop, Shoper or Shopify - the invoice flow is then designed once, for all channels.
Where to start on your side
I start with a free diagnosis: I look at where your orders actually come from, which accounting program you already use and where manual work is created today. Usually that conversation ends with the realisation that the tools you already pay for just need configuring correctly - and I say so plainly, even when it means no work for me.
When real coding is needed (a custom Allegro API integration, wiring in an ERP, unusual document rules), you get scope and price in writing before the start. The order and document flow I set up under optimization, and after go-live it can be kept under ongoing technical support - Basic from 1,000, Pro from 2,000, Premium from 3,500 PLN net per month, depending on how critical that sales channel is.
Frequently asked questions
Does an Allegro accounting integration issue invoices automatically? Yes - once the accounts are connected, the program pulls paid orders and creates documents for them according to the rule you set. You have to decide once when the document should be created, which numbering series to use and what to do with orders that have no VAT number.
Can Allegro be connected to iFirma, wFirma, inFakt or Subiekt? Yes, all the popular Polish accounting and trading programs now connect to Allegro, either directly or through an order manager. The differences lie in the details: handling returns, credit notes, delivery costs and whether the document goes back onto the Allegro order automatically.
Do Allegro invoices have to go to KSeF? Invoices issued to businesses go through KSeF, because the system has applied to all taxpayers since April 2026. Named documents for consumers are broadly outside that flow, but it is your accounting program that has to get the classification right - so choose one that supports KSeF natively.
How long does implementing automatic Allegro invoices take? Configuring an off-the-shelf integration is usually one day of work including tests on a few orders. A custom Allegro API integration wired into an ERP or an unusual process is a project measured in weeks - I give the specific deadline after looking at your flow, together with the quote.
Running a store where something does not work the way it should? I build and rebuild WooCommerce stores - from a single fix to reworking the whole sales flow. Tell me what you are dealing with and I will send back a scope and a price.