Accounting for marketplaces: A guide to taxes, settlements, and automation in e-commerce

The marketplace model has come to dominate modern e-commerce. Instead of building a traditional store and tying up capital in inventory, more and more entrepreneurs are choosing to create platforms that connect buyers with sellers—much like Allegro or Amazon. However, this scalable business model brings significant back-office challenges. Accounting for a marketplace is vastly different from managing the books for a standard online store. It requires a combination of expertise in tax law, international settlements, and advanced IT system integration. 

At Besides Finance, we specialize in supporting modern digital business models. Every day, we manage the accounting for over a dozen active marketplace platforms. We know exactly how to structure these processes from practical experience. We have prepared a comprehensive guide that will walk you through the biggest accounting and tax challenges associated with running such a platform, step by step.

Business model and taxes: Intermediary or seller?

The first and most important step in setting up your accounting correctly is defining your platform's role in the eyes of the law. For the tax authorities, it is crucial whether you act as an intermediary (agent) or as an entity that buys and resells goods (reseller).

• Agency model (intermediation): The marketplace only provides the infrastructure. The parties to the purchase agreement are the buyer and the external seller directly. The platform's revenue consists solely of the commission or subscription fee collected. However, this requires caution to ensure the tax office does not determine that you are actually buying and selling the goods yourself.
• Reseller model: The platform formally acquires the goods from the supplier at the moment the customer places an order and immediately resells them. In this case, the revenue is the entire amount paid by the customer, and the cost is the purchase of the goods.

The vast majority of platforms operate under the agency model, which creates specific consequences for document flow and the accounting of funds.

What accounting challenges do marketplace operators face? (5 key areas)

1. How to correctly account for commissions and payment gateway flows? 

When a customer pays for a cart containing products from three different sellers, the entire amount initially goes to the platform's account or the payment operator (e.g., Stripe, Mangopay, or dedicated solutions like Przelewy24 Marketplace). From an accounting perspective:

• Money paid by the customer for goods is not marketplace revenue. These are so-called third-party funds, which are recorded in clearing accounts.
• The platform's revenue is only the margin/commission that the operator deducts before transferring the funds to the seller. The accounting department must be able to precisely separate these streams in the books, based on detailed reports from payment gateways (payout reports).

2. What is the DAC7 directive? 

Since July 1, 2024, digital platform operators in Poland have had a new, very important obligation resulting from the EU's DAC7 directive (in most EU countries it has been in force since 2023, and Polish regulations also retroactively covered 2023 for reporting purposes). Marketplaces must collect, verify, and report detailed data to the tax office regarding sellers active on the platform and the income they earn. This requires:

• Implementing seller identity verification procedures (KYC).
• Monitoring sales thresholds (exemptions from reporting include, among others, sellers of goods who have completed fewer than 30 sales transactions during the year, provided their total remuneration did not exceed 2,000 EUR—this exemption does not apply to services or rentals).
• Generating and submitting structured reports to the Head of the National Revenue Administration (KAS) by the end of January for the previous year. Failure to comply can result in penalties of up to PLN 1 million.

3. How does international sales affect VAT and when does VAT OSS apply? 

If your marketplace facilitates international transactions, VAT regulations become exceptionally complex. This applies not only to the sale of goods but also to the commission itself: if the seller is a company from another country, the brokerage service is typically invoiced without Polish VAT, and the tax is accounted for by the buyer (reverse charge). This requires verifying the seller's EU VAT number and reporting the service in the recapitulative statement.

• VAT OSS (One Stop Shop): Once the EUR 10,000 threshold for annual distance sales to consumers in other EU countries is exceeded, VAT must be settled according to the rates of the buyer's country. The OSS procedure allows this to be done in a single declaration filed with the Polish tax office, without the need for registration in each country. However, you must ensure the correct VAT rates for the consumer's country are applied.
• "Deemed Supplier" Rule: This is a trap for many operators. If your marketplace facilitates the sale of goods imported from outside the EU (e.g., from China) in packages valued up to EUR 150, the platform (not the seller!) is treated by law as if it had purchased and resold the goods. This means the marketplace must collect and remit VAT on this transaction, most often using the IOSS (Import One Stop Shop) procedure. The same rule applies to the sale of goods already located in the EU (e.g., in a warehouse in Poland) to consumers if the seller is based outside the EU, regardless of the shipment value.

4. How to automate the management of thousands of microtransactions? 

Marketplaces generate hundreds or thousands of transactions daily. Manually issuing commission invoices for every seller at the end of the month is physically impossible. Accounting for this model must be based on advanced automation and dedicated IT solutions.

That is why at Besides Finance, we have developed a dedicated integration with Stripe. It identifies, categorizes, and records financial flows at the level of each individual transaction—including commission settlements, multiple currencies, exchange rate differences, and the VAT OSS procedure. In practice, this allows for the efficient handling of thousands of transactions per month while maintaining full tax compliance.

Eliminating manual payment reconciliation saves teams dozens of hours of work each month and removes the risk of errors in payment mapping. Organized records also facilitate preparation for due diligence, and constant access to reliable data in real time—supported by our business analytics tools —significantly speeds up performance reporting to investors.

Then there is the mandatory KSeF. Every commission invoice issued to Polish sellers must be sent to the National e-Invoice System, which, with thousands of settlements, rules out manual work. That is why we use the S2KSeFapplication, which automates the sending of invoices issued in Stripe directly to KSeF. See more in our article: KSeF and Stripe – how to integrate payments with e-invoices.

5. How to handle returns, chargebacks, and commission adjustments? 

Returns are a constant element of any e-commerce business. In a marketplace model, a product return to the seller triggers a financial chain: the customer receives a refund, the seller must issue a sales correction, and the marketplace must adjust the commission charged and return it to the seller (or deduct it from the next settlement). Managing these deductions and correctly reflecting them on credit notes requires a flawlessly programmed billing system. Chargebacks, which are payment reversals initiated by the customer's bank, are a separate category: the payment operator deducts the disputed amount along with a fee, and the platform must determine (ideally in its terms and conditions) who bears this cost—the seller or the marketplace—and account for it correctly.

How to prepare the IT and legal infrastructure for marketplace accounting?

If you are planning to launch or scale your platform, ensure you have these foundations in place:

• Choose a "Marketplace" payment gateway: Solutions like Stripe Connect or Mangopay are designed to automatically split payments between transaction participants. They automatically distribute funds between the seller and the platform's commission, which drastically simplifies subsequent reporting.
• Terms and Conditions and the moment of revenue recognition: From the tax office's perspective, the terms and conditions must clearly define when the brokerage service is performed (e.g., at the time of payment for the order or at the time of delivery) and when the commission is charged. This determines the date of the tax obligation.
• Exporting clean financial data: Ensure your IT team can generate settlement reports from the system—files (e.g., CSV, XLS) that the accounting department can upload to financial and accounting software to collectively book commissions and settlements with sellers.

Frequently Asked Questions

Is the money from customers flowing into the marketplace's account considered its revenue?

No. In an agency model, the platform's revenue consists solely of the commission. Funds due to sellers are third-party funds recorded in settlement accounts.

Does a small marketplace also have to report under DAC7?

Yes—the obligation applies to every platform operator, regardless of size. Only certain sellers are excluded from the report, such as those who have completed fewer than 30 transactions with a total value of up to 2,000 EUR per year.

When does a marketplace become a VAT taxpayer for the sale of goods?

When it facilitates the sale of imported goods in shipments of up to 150 EUR or the sale of goods located in the EU by non-EU sellers to consumers. In such cases, it is treated as a "deemed supplier."

Do commission invoices for sellers need to be sent to the KSeF?

Yes, invoices issued to Polish companies are subject to the mandatory KSeF. With a large number of settlements, it is best to automate their issuance and delivery, for example, directly from Stripe.

Summary: How to scale a marketplace without the chaos?

Managing marketplace accounting is a process where flaws in financial architecture can cost a company a loss of liquidity, while gaps in procedures (such as DAC7) can lead to heavy penalties. This requires an accounting firm to have not only an excellent grasp of tax regulations but also an understanding of data flows, API operations, and modern financial technologies.

At Besides Finance, we don't just process documents; we act as financial architects. We know exactly how to do this in practice because we work with marketplace clients every day. We help map transaction processes, advise on payment system selection, and implement our proprietary integrations that fully automate accounting and business analytics—taking the entire burden of settlements off the platform operator's shoulders.

If your current settlement model is overwhelming you or you are planning an expansion that requires organizing your financial data, get in touch with us or book a free consultation. Let’s talk about how we can optimize accounting for your marketplace.