Postscale Invoices
Send and receive legally compliant e-invoices via email. XRechnung, ZUGFeRD, and EN 16931 — through one API.
Germany's B2B E-Invoicing Mandate
Starting January 2027, all German businesses with revenue above EUR 800K must issue structured e-invoices. By January 2028, every business must comply. Email is a valid transmission channel.
Businesses > EUR 800K
All businesses
Start integrating now — be ready before the mandate.
How It Works
Receive
Inbound emails with XRechnung or ZUGFeRD attachments are automatically detected, parsed, and validated.
Validate
Free validation API checks any XML against EN 16931 and XRechnung rules. Use it without limits.
Send
Generate compliant XRechnung XML from JSON and send via email with DKIM signing and delivery tracking.
Built for E-Invoicing
Email-Native
Built on production email infrastructure with DKIM, SPF, and DMARC. Invoices delivered reliably.
API-First
RESTful API for validation, sending, and receiving. SDKs for popular languages.
XRechnung & ZUGFeRD
Full support for XRechnung UBL 2.1, UN/CEFACT CII, and ZUGFeRD hybrid PDFs.
Webhook Delivery
Receive structured invoice data via webhooks with seller, buyer, line items, and VAT details.
DKIM-Signed Delivery
Outbound invoices are DKIM-signed and sent through warmed infrastructure for maximum deliverability.
EN 16931 Compliant
Validation against the full EN 16931 standard with the German CIUS (XRechnung) rules.
Validate in Seconds
The validation API is free for all Postscale users. No feature flag, no plan restriction.
curl -X POST https://api.postscale.io/v1/invoices/validate \
-H "Authorization: Bearer ps_live_..." \
-H "Content-Type: application/xml" \
-d @invoice.xml
# Response
{
"valid": true,
"format": "xrechnung-ubl",
"standard": "EN 16931",
"errors": [],
"warnings": []
}Pricing
Validation API
Validation API — unlimited, no restrictions
Inbound & Outbound
Processing and sending invoices — included in paid plans during early access
Request Early Access
Join the waitlist for Postscale Invoices. We'll notify you when your account is enabled.