Reverse charge lets B2B EU customers receive your invoice with 0% VAT instead of the standard rate (19–27%). The buyer self-assesses and reports the tax. The catch: you need a verified VIES VAT number for every B2B customer. Self-declared B2B without verification doesn't qualify — and in our data, 38% of customers who tick "business" at checkout enter an invalid or missing VAT ID. If you get this wrong, the audit is on you, not them.
Every B2B SaaS company selling to the EU eventually discovers reverse charge and gets excited. Here's why: instead of collecting and remitting 19–27% VAT on a German, French, or Italian B2B sale, you can invoice without VAT, mark it "reverse charge," and your customer handles the tax on their side. It's clean, simple, and the customer prefers it because they don't have to wait for a refund.
The excitement lasts until you read Article 196 of the VAT Directive (Council Directive 2006/112/EC) and realise the conditions are stricter than they look — and that getting them wrong puts the audit liability squarely on the seller.
What reverse charge actually is
Reverse charge is a mechanism in EU VAT law that shifts the responsibility for VAT accounting from the seller to the buyer in certain cross-border B2B transactions. The seller invoices without VAT. The buyer self-assesses VAT on their own VAT return, in their own country, and almost always claims an offsetting input credit in the same return — meaning the net VAT effect is zero.
For digital services (which is most AI and SaaS), reverse charge applies when:
- The seller is established outside the buyer's member state (so: a US AI co selling into Germany qualifies).
- The buyer is a taxable person (a business, not a consumer).
- The buyer is registered for VAT in their member state and has supplied a valid VAT ID.
- The seller has verified that VAT ID through the EU's VIES system (VAT Information Exchange System).
All four conditions must hold. The last one is where everything breaks.
The VIES verification problem
VIES is the EU's VAT-number-validation API. You hit ec.europa.eu/taxation_customs/vies with a country code + VAT number and get back a yes/no plus the company name/address registered for that VAT number.
VIES has four operational quirks that bite at scale:
- Country-by-country availability. Some member states' databases go offline for hours per week (looking at you, Italy). VIES returns "service unavailable." A "service unavailable" result is not the same as a valid verification.
- Name/address matching is optional. VIES will tell you the VAT ID exists. It will sometimes return the registered company name. Whether that name matches the one your customer typed at checkout is your job to check.
- Time-of-supply matters. Verification must happen at the time of supply. A VAT ID that was valid 6 months ago when the customer signed up isn't enough. EU auditors will ask for the verification timestamp.
- Rate limits. VIES rate-limits to roughly 1,000 queries per hour per IP. High-volume sellers (us, you) need to batch and cache, with explicit awareness of cache TTL.
Why 38% of self-declared B2B buyers fail verification
We tracked verification outcomes for 480,000 self-declared business checkouts across our platform in 2024–2025. The breakdown:
That 38% who fail verification still ticked "I'm a business" at checkout. Some are individual freelancers who genuinely don't have a VAT number (under registration thresholds). Some are companies whose finance team forgot to register for VAT. Some are typing the wrong field (e.g. their tax ID instead of their VAT ID — they're different in most EU countries).
For each of those 38%, you cannot apply reverse charge. You have to treat the sale as B2C and charge the standard VAT rate of the buyer's country.
The fallback when VAT ID verification fails
Two options. Pick one and document the policy:
Option A: hard-require valid VAT ID for B2B price
If the customer claims B2B but can't produce a verifiable VAT ID, you charge them the B2C rate (the country's standard VAT) on top of the listed price. They can try again with a corrected VAT ID; if it verifies on the next attempt, you can refund the VAT and reissue the invoice as reverse charge.
Pros: clean tax position, no exposure. Cons: friction, some abandoned checkouts.
Option B: default to B2C, allow VAT ID upload later
Charge VAT-inclusive at checkout. If the customer later supplies and verifies a VAT ID, you can issue a corrective credit note and refund the VAT portion.
Pros: lower friction. Cons: 60–90 day refund cycles, double-bookkeeping, and you have to handle the case where a customer demands the refund after the input-credit window closes for their own VAT period.
Option A at checkout. If you sell at low ticket ($20-$50/mo) and you can't afford the abandonment, Option B with a clearly disclosed 30-day refund window. Document your decision in your tax policy file; auditors will ask.
Invoice rules under reverse charge
A reverse-charge invoice has specific required content. Missing any of these can void the reverse charge treatment and shift liability back to you in an audit:
- The seller's name, address, and VAT/tax ID (your US EIN works for non-EU sellers).
- The buyer's name, address, and verified VAT ID.
- The phrase "Reverse charge" (or its translated equivalent — "Umkehrung der Steuerschuldnerschaft" in German, "Autoliquidation" in French, etc.).
- Reference to the EU VAT Directive: "Article 196 of Council Directive 2006/112/EC."
- Date of supply (used to anchor the verification timestamp).
- Total amount, with no VAT line and no VAT rate.
Audit exposure if you get reverse charge wrong
If you apply reverse charge but the conditions weren't met (no valid VAT ID, no verification, buyer wasn't actually a taxable person), the seller — i.e. you — is liable for the VAT that should have been collected. Plus penalties and interest.
Typical penalty stack for an unsupported reverse-charge invoice in an EU audit:
| Component | Typical |
|---|---|
| Back VAT owed | 19–27% of net supply |
| Late payment interest | 4–10% APR depending on member state |
| Penalty for incorrect invoice | 10–50% of the VAT amount |
| Penalty for late filing if discovered cross-audit | fixed per invoice |
At scale, this is real money. We've cleaned up reverse-charge errors for AI companies post-audit that ran to €280,000 in back tax + penalties on ~$3M of unsupported B2B EU revenue.
How we implement reverse charge in checkout
Macropay's checkout does the following on every EU sale:
- Detect billing country via geolocation + buyer-provided address.
- Default to B2C VAT rate for the country.
- If buyer ticks "business," show a VAT ID input.
- On submit, call VIES in real-time. Cache the result with a 24-hour TTL.
- If VIES returns valid AND the registered name reasonably matches: apply reverse charge, drop the VAT line, mark invoice with the required phrasing.
- If VIES returns invalid, no-match, or service-unavailable: fall back to B2C rate, show the customer the breakdown clearly, allow them to retry with a corrected VAT ID before checkout completes.
- Store the VIES query and response with the invoice for audit trail.
Because Macropay is the Merchant of Record, that audit trail sits in our database, not yours. If an EU auditor wants to see VIES timestamps from a sale 18 months ago, we have them. If we don't, the bill is ours, not yours.
We spent four months building VIES caching with proper invalidation, then three more building the invoice-corrective flow. Then we found out we'd been cross-classifying half our Dutch B2B customers as B2C anyway. We moved to Macropay for the audit trail more than the tax savings.— Andrei Volkov, CTO, Lattix.ai
For the bigger picture of EU VAT exposure and how OSS, IOSS, and MOSS schemes layer on top of reverse charge, see our piece on VAT, GST, and the 92 jurisdictions on your balance sheet and our walkthrough of which EU VAT scheme actually applies.