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73 /100 GO Medium complexity

DowodVault — proof vault for Poland's KSeF B2B sellers

Binds every contract, delivery note and PO to its KSeF invoice for one-click proof of any disputed sale.

Compliance SaaS EU PolandCompliance-drivenSMBDocument-AIKSeFSolo-builder
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Evaluation Scores
73/100

GO

Overall Score

15
Problem
12
Demand
11
Build
11
Distrib.
11
Revenue
8
Time
5
Defense

DowodVault — supporting-document vault for Poland’s KSeF B2B sellers

1. One-liner

Binds every contract, delivery note and PO to its KSeF invoice so a disputed sale produces its full proof in one click.

2. Trend signal — why now?

Poland switched on the Krajowy System e-Faktur (KSeF) for B2B as a hard mandate: large taxpayers from 1 February 2026, and every other VAT-registered business from 1 April 2026 (micro-entrepreneurs follow 1 Jan 2027). The whole Polish B2B economy is now issuing structured XML invoices through a government clearing system.

Here’s the part nobody productized: KSeF holds the invoice and refuses to hold the documents that prove it. The official guidance and every Big-4-adjacent advisory says the same thing — contracts, delivery notes (WZ), acceptance protocols, transport documents and annexes “trzeba będzie wysyłać poza KSeF” (must be sent outside KSeF) and remain the taxpayer’s own archival responsibility. The FA(3) “Załącznik” attachment node that launched 1 Feb 2026 is deliberately narrow: it requires advance notification to the tax office, only works through commercial API tools (not the free Ministry tool), and explicitly excludes “marketing, commercial or contractual documents (price lists, contracts, guarantees…).” So the supporting paper trail is structurally orphaned — and advisors are openly telling firms to “build your own digital archive” for exactly these excluded documents.

KSeF stores the invoice for 10 years automatically. It stores none of the evidence you’d need the day a buyer short-pays and says “we never received those goods” or an auditor asks you to substantiate the transaction. That bundle lives in email, a paper binder, and a shared drive — scattered the moment you most need it together.

Provenance:

3. The opportunity

The KSeF compliance market is a gold rush — Comarch, Symfonia, Base, EDICOM, ifirma and a dozen others are all selling “issue and receive your e-invoices correctly.” That fight is over and crowded.

The orphaned layer is the supporting documents. Every accounting/ERP vendor is racing to make the invoice compliant. None of them owns the workflow of capturing the contract, PO, delivery note (WZ) and acceptance protocol and binding each one to the matching KSeF invoice number, so that on demand — a payment dispute, a chargeback, a VAT/CIT audit, a debt-collection case — the seller produces the complete, dated, immutable evidence bundle for that single transaction in one click.

The incumbents do invoicing. DowodVault does proof. It sits next to whatever invoicing tool the firm already uses (read-only KSeF API access by KSeF number), so it’s not a rip-and-replace and not competing for the invoicing seat. It’s the missing evidence cabinet the mandate created on the day it launched.

4. Target market

  • Primary customer: Polish B2B sellers, 2M–50M PLN annual turnover, that ship physical goods or deliver contracted work where a single invoice rests on a delivery note + PO + contract: building-materials and industrial wholesalers, manufacturing subcontractors, equipment-service firms, transport/logistics SMEs, B2B distributors. Owner/CFO/head-of-finance is the buyer; the external biuro rachunkowe (accounting office) is the influencer and channel.
  • Why they buy (in their words): “KSeF holds my faktura but not the WZ or the umowa — and when a klient disputes the delivery, that’s exactly what I have to dig out of email.” Losing a single disputed B2B invoice in this segment is 5,000–50,000 PLN; one prevented loss pays for years of subscription.
  • Rough TAM reasoning: From 1 Apr 2026 every VAT-registered B2B business in Poland is in KSeF — well over 2 million entities, of which a few hundred thousand are goods/project sellers in the target turnover band who genuinely carry supporting-document risk. Capture even 5,000–10,000 of them and this is a 1M–5M PLN/yr (≈$250K–$1.2M ARR) business; the segment is far larger.
  • Why now for them: The mandate forces them to rewire how invoices flow this quarter. Their supporting documents just got separated from their invoices by law, and they feel the gap on the first disputed transaction after 1 April.

5. Product sketch (MVP)

  • KSeF sync (read-only): Connect via KSeF API; pull issued and received invoices with their KSeF numbers, buyer NIP, amounts and line items into a searchable register.
  • Drop-the-proof capture: Forward an email, upload a scan, or snap a phone photo of a WZ / PO / contract / acceptance protocol; the document lands in an inbox waiting to be matched.
  • Auto-match: AI reads each supporting document (OCR + LLM), extracts counterparty NIP, dates, amounts and order/delivery numbers, and proposes the KSeF invoice it belongs to. One-click confirm or correct.
  • Evidence bundle, one click: For any invoice, generate a dated PDF dossier — KSeF invoice + every bound supporting document — ready to send to a disputing buyer, a debt-collection lawyer, or an auditor.
  • Gap radar: Flags invoices over a threshold that have no bound delivery note or contract — i.e., invoices you couldn’t defend if challenged today.
  • Immutable, timestamped archive: WORM-style storage with a tamper-evident log, retained for the statutory period (KSeF excludes these docs from its own 10-year retention).
  • Accountant view: Read access for the firm’s biuro rachunkowe so they can pull the bundle during audits without phoning the client.

6. AI angle — what’s load-bearing

The product is worthless without reliable document-to-invoice matching. A delivery note rarely cites an invoice number — it cites an order number, a date, a counterparty and a list of goods. Matching it to the right KSeF invoice means reading messy scanned WZ/PO/contract documents (Polish, varied layouts, handwriting on delivery confirmations) and reconciling extracted entities (NIP, dates, amounts, quantities) against the structured invoice data. That’s exactly the OCR+LLM extraction-and-reconciliation task that only became cheap and accurate enough in the last 18 months. Remove the AI and you’re back to a human manually tagging every document to every invoice — which is the status quo nobody does, which is why the evidence is always scattered. AI is the entire reason this is a 2-minute job instead of a 2-hour one.

7. Localization angle

This is a Poland-native play and that’s the whole moat-by-focus. The product is defined by KSeF’s specific rules: the KSeF number as the binding key, the FA(3) attachment exclusions, Polish document types (WZ, faktura, protokół odbioru), Polish-language OCR, NIP validation, and the statutory retention/przedawnienie periods. The buyer expects a Polish UI, PLN pricing (a 99–249 PLN/mo tier where a generic $99 tool feels alien), and integration into the biuro-rachunkowe relationship that runs Polish SME finance. A generic global “document management” tool cannot wedge here because it doesn’t speak KSeF. This is regulatory arbitrage where the regulation is the product spec.

8. Business model — path to $1M–$5M ARR

  • Pricing: 99 PLN/mo Solo (1 user, <500 invoices/mo), 199 PLN/mo Standard (multi-user, accountant access, gap radar), 399 PLN/mo Pro (high volume + API + bulk export). ~$25–$100/mo equivalents.
  • ACV: 2,400 PLN ($600) blended.
  • Rough math to $1M ARR (~4M PLN): ~1,650 customers × 199 PLN × 12 ≈ 3.9M PLN. Out of a 2M+ business mandate pool, that’s a <0.1% capture rate.
  • Rough math to $5M ARR (~20M PLN): ~8,000 customers at blended ACV, or fewer with an upsell to a per-bundle e-signature / debt-pack add-on and a white-label tier sold through accounting offices to their whole client books.
  • Expansion path: seats (more finance staff), volume tiers, an outbound “dispute pack” generator (priced per pack), and the biuro-rachunkowe white-label channel where one firm onboards 50–200 clients at once.

9. Go-to-market wedge — first 100 customers

  • Biuro rachunkowe channel (primary): There are tens of thousands of accounting offices in Poland, each managing dozens-to-hundreds of B2B clients and each currently being asked by those clients how to handle KSeF supporting docs. Sign 15–20 offices on a revenue-share/white-label deal; each brings 20–100 clients. This is the fastest path to 100 paying seats and the cheapest CAC.
  • Targeted outbound to goods sellers: Pull B2B wholesalers/distributors/manufacturers in the 2M–50M PLN band from the Polish business registry (KRS/REGON) filtered by PKD codes for wholesale/manufacturing; send a Polish cold email + 90-second Loom: “KSeF nie przechowuje Twoich WZ i umów. Pokażemy, jak wiązać je z fakturą.” Expect 2–4% reply in a freshly-painful, mandate-driven market.
  • KSeF content + accountant communities: Polish accounting/SME Facebook groups, GoldenLine/LinkedIn KSeF threads, and r/Polska / branżowe forums are full of “co z załącznikami do KSeF?” questions right now. Answer them with a concrete how-to and the tool, where the audience is already actively searching.
  • Partner with one mid-tier KSeF invoicing vendor that does invoices but not document binding — integrate as their “evidence” add-on rather than compete.

10. Build complexity — justification

Medium. Off-the-shelf: KSeF API integration (documented, REST/XML), OCR + LLM document extraction, WORM object storage, standard web stack. The custom work is the matching engine — reliably binding a scanned WZ/PO/contract to the correct KSeF invoice across Polish layouts and fuzzy fields — plus the audit-grade immutability/retention guarantees. A pair could ship a credible v1 in 3–4 months: KSeF sync + manual binding first, then layer auto-match. The matching accuracy is the technical risk, not the plumbing.

11. Gating checklist

GatePass?Note
Legal in target market✅Read-only KSeF API; storing one’s own business documents is standard and required.
Ethical — no harm / dark patterns✅Helps SMEs defend legitimate transactions; no manipulation.
Market exists (evidence above)✅2M+ businesses mandated; supporting-doc exclusion documented by official + advisory sources.
1–5 person team can build this✅Pair can ship v1 in 3–4 months.
Launchable with <$50K / ₹40L✅API + cloud + LLM inference; minimal capex.

All five pass.

12. Feasibility score

AxisWeightScoreNotes
Problem intensity2015/20Real, recurring, money-on-the-line on every dispute/audit — but felt sharply only when a dispute hits, not daily. Below hair-on-fire.
Demand evidence1512/15Mandate is hard fact; exclusion of supporting docs documented by official + multiple advisory sources; incumbent compliance spend proves wallet. Direct “I’d pay for the binding tool” customer quotes still thin.
Build feasibility1511/15Plumbing is off-the-shelf; matching engine + audit-grade retention is the real work. 3–4 months for a pair.
Distribution clarity1511/15Biuro-rachunkowe channel is concrete and high-leverage; registry-filtered outbound is concrete. Channel conversion unproven.
Revenue mechanics1511/15Pricing benchmarked against KSeF tooling (23–500 PLN/mo); $1M ARR needs <0.1% of pool. PLN price ceiling caps ACV.
Time to first revenue108/10Mandate just hit; pain is acute now; an accountant-office pilot can pay within weeks of a usable v1.
Defensibility105/10Moat is focus + accountant-channel lock-in + accumulating bound-document data per client. A KSeF incumbent could bolt this on — but they’re busy with invoicing. Copyable in ~6–12 months.
Total10073/100

13. Qualitative modifiers

Founder-fit tags

technical-heavy (KSeF API + matching engine) · domain-expertise-required (Polish KSeF rules, document types, retention law; ideally a Polish founder or one paired with a Polish accountant advisor).

Key assumptions to validate (3–5)

  1. Assumption: Goods/project sellers in the 2M–50M PLN band feel real pain that supporting docs are orphaned from KSeF invoices. How to test: 25 interviews via 3–4 accounting offices; ask how they’d produce a delivery note + invoice for a disputed sale today and how long it takes.
  2. Assumption: Biuro rachunkowe offices will resell/recommend a per-client tool (revenue share). How to test: pitch 10 offices a white-label deal; target ≥3 signed pilots.
  3. Assumption: Auto-match accuracy on real Polish WZ/PO/contract scans is high enough to be trusted (>90% correct binding). How to test: collect 200 real document/invoice pairs, measure match precision before building the full UI.
  4. Assumption: PLN 199/mo is acceptable. How to test: price-test against framing “cost of one lost disputed invoice.”

Risk flags

  1. Platform dependency: Entirely tied to KSeF API stability and rules; the FA(3)/attachment regime could evolve (or the Ministry could later store supporting docs itself, collapsing the gap). Monitor MF announcements.
  2. Incumbent encroachment: Comarch/Symfonia/ifirma could add document-binding as a feature; mitigate with accountant-channel lock-in and speed.
  3. Market timing: Pain is acute now through 2026–27 onboarding; if not in-market by the 1 Apr 2026 wave + the 2027 micro wave, the wedge cools as firms settle into makeshift workarounds.
  4. Demand-evidence gap: Strong structural logic, thinner direct “shut up and take my money” signal — the reason this is a 73/GO, not an 80.

14. Structured verdict

Score:                  73/100
Verdict:                GO
Confidence:             Medium
Best-fit builder:       Polish technical founder (or pair) with a biuro-rachunkowe / KSeF advisor
Time to revenue:        6–10 weeks after a usable v1 (accountant-office pilot)
Capital to launch:      ₹4–8 lakh ($5–10K) — API, cloud, LLM inference, registry data
Top 3 assumptions to validate first:
  1. Sellers feel the orphaned-document pain enough to pay — 25 interviews via 3 accounting offices
  2. Biuro rachunkowe offices will resell white-label — pitch 10, target ≥3 pilots
  3. Auto-match precision >90% on real Polish WZ/PO/contract scans — 200-pair test before full build
Kill criteria:
  - Abandon if <3 of 10 pitched accounting offices want to resell after the demo
  - Abandon if auto-match precision stays below 80% on real documents after 8 weeks of tuning
  - Abandon if a major KSeF incumbent ships invoice-bound supporting-document storage before your v1

15. Next step — 1-week validation sprint

  • Day 1–2: Recruit 3 accounting offices and 10 B2B goods sellers in the target band. Land a Polish demo page: “KSeF nie przechowuje Twoich WZ, umów i protokołów — DowodVault wiąże je z fakturą.” Capture email sign-ups.
  • Day 3–4: Run 15–20 interviews. Walk each through reconstructing a disputed sale’s evidence today; time it. Ask the accounting offices directly: would you resell this to your clients, and at what share?
  • Day 5: Decide go / no-go. Go only if ≥40% of interviewed sellers say they’d pay ≥199 PLN/mo and ≥3 of the accounting offices commit to a reseller pilot. Anything less and the structural gap is real but the willingness-to-pay isn’t proven — drop to VALIDATE and re-test pricing.

The result is falsifiable: a named count of paying intents and signed accountant pilots, not “people liked the idea.”

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