Embed Liberation Sans in invoice PDFs for PDF/A-3 compliance (v0.2.6)

An E-Rechnung checker flagged that generated invoices don't embed their
fonts. Both invoicePdf.tsx and correctionInvoicePdf.tsx used react-pdf's
built-in Helvetica/Helvetica-Bold, which is never embedded — PDF/A-3
(already required by this package's own Factur-X/ZUGFeRD pipeline) has
no exemption for standard fonts. Vendors Liberation Sans (SIL OFL-1.1,
metrically identical to Helvetica) and registers it via Font.register in
a new fonts.ts, imported by both PDF modules.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

README.md

@@ -33,6 +33,8 @@ One canonical implementation, consumed by both repos, makes this class of drift
 
 **2026-07-25, unpaid-notice layout fix (v0.2.4).** The new unpaid-Vorkasse instruction (v0.2.3) reused `paidBadgeRow`, which lives inside `summary`'s `alignItems: "flex-end"` column (240pt-wide, designed for the short one-line paid confirmation) — so the longer two-sentence instruction shrank to content width and read as squeezed under the narrow summary card instead of a proper full-width note. Moved to its own sibling row (`unpaidNoticeRow`, `width: "100%"`, `marginTop: 20` vs. `paidBadgeRow`'s 10) outside `summary` entirely, left-aligned instead of right-aligned.
 
+**2026-07-28, embedded font (v0.2.6).** An E-Rechnung/PDF-A checker flagged that generated invoice PDFs don't embed their fonts — both `invoicePdf.tsx` and `correctionInvoicePdf.tsx` used react-pdf's built-in `Helvetica`/`Helvetica-Bold`, one of the "standard 14" PostScript fonts react-pdf never actually embeds (it just emits a `/BaseFont` reference and relies on the PDF viewer having a substitute installed). PDF/A-3 — already required by this package's own Factur-X/ZUGFeRD pipeline (see "E-invoicing" below) — has no exemption for standard fonts; every font actually used must be embedded. Fixed by vendoring `LiberationSans-Regular.ttf`/`LiberationSans-Bold.ttf` (SIL OFL-1.1, metrically identical to Helvetica/Arial — no layout shift) under `src/assets/fonts/`, registered once via `Font.register()` in the new `fonts.ts` (imported for its side effect by both PDF modules), with every `fontFamily: "Helvetica"`/`"Helvetica-Bold"` replaced by `fontFamily: "Liberation Sans"` (+ `fontWeight: "bold"` where the bold variant was used). Verified by inspecting the raw PDF bytes of a generated fixture: `/FontFile2` present, `/BaseFont` shows subset tags (e.g. `CWOPQE+LiberationSans`), `/Subtype /Type0` — i.e. actually embedded, not just referenced.
+
 ## How this is consumed
 
 Not published to npm — installed as a git dependency:
@@ -51,6 +53,7 @@ Ships raw TypeScript/TSX source (no build step) via `main`/`types` pointing stra
 - `formatters.ts` — `formatPrice()`/`formatDate()`, canonical formatting for every document.
 - `invoicePdf.tsx` — the original invoice ("Rechnung"): `InvoiceDocument`, `renderInvoicePdf()`, plus `SAMPLE_INVOICE_ORDER` (used by the frontend's Payload Live Preview for company-settings).
 - `correctionInvoicePdf.tsx` — Stornorechnung/Gutschrift: `renderCorrectionInvoicePdf()`.
+- `fonts.ts` — registers the embedded Liberation Sans font (`src/assets/fonts/`) once for both PDF modules — see the 2026-07-28 changelog entry above.
 - `seller.ts` — the shared `InvoiceSeller` type both document types render in their footer.
 - `einvoice/` — the ZUGFeRD/Factur-X layer (see "E-invoicing" below).
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@einfach-produktiv/invoicing",
-  "version": "0.2.5",
+  "version": "0.2.6",
   "private": true,
   "description": "Shared invoice / correction-invoice (Stornorechnung, Gutschrift) PDF generation and VAT-breakdown math, consumed as a git dependency by both the einfach-produktiv frontend and the payload backend — not published to npm.",
   "type": "module",

src/assets/fonts/LICENSE-OFL.txt

@@ -0,0 +1,130 @@
+Format: https://www.debian.org/doc/packaging-manuals/copyright-format/1.0/
+Upstream-Name: Liberation Fonts
+Source: https://github.com/liberationfonts
+
+Files: *
+Copyright:
+ Digitized data copyright (c) 2010 Google Corporation with Reserved Font Arimo, Tinos and Cousine.
+ Copyright (c) 2012 Red Hat, Inc. with Reserved Font Name Liberation.
+License: SIL-OFL-1.1
+ This Font Software is licensed under the SIL Open Font License,
+ Version 1.1.
+ .
+ This license is copied below, and is also available with a FAQ at:
+ http://scripts.sil.org/OFL
+ .
+ SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
+ .
+ PREAMBLE The goals of the Open Font License (OFL) are to stimulate
+ worldwide development of collaborative font projects, to support the font
+ creation efforts of academic and linguistic communities, and to provide
+ a free and open framework in which fonts may be shared and improved in
+ partnership with others.
+ .
+ The OFL allows the licensed fonts to be used, studied, modified and
+ redistributed freely as long as they are not sold by themselves.
+ The fonts, including any derivative works, can be bundled, embedded,
+ redistributed and/or sold with any software provided that any reserved
+ names are not used by derivative works.  The fonts and derivatives,
+ however, cannot be released under any other type of license.  The
+ requirement for fonts to remain under this license does not apply to
+ any document created using the fonts or their derivatives.
+ .
+ .
+ .
+ DEFINITIONS
+ "Font Software" refers to the set of files released by the Copyright
+ Holder(s) under this license and clearly marked as such.
+ This may include source files, build scripts and documentation.
+ .
+ "Reserved Font Name" refers to any names specified as such after the
+ copyright statement(s).
+ .
+ "Original Version" refers to the collection of Font Software components
+ as distributed by the Copyright Holder(s).
+ .
+ "Modified Version" refers to any derivative made by adding to, deleting,
+ or substituting ? in part or in whole ?
+ any of the components of the Original Version, by changing formats or
+ by porting the Font Software to a new environment.
+ .
+ "Author" refers to any designer, engineer, programmer, technical writer
+ or other person who contributed to the Font Software.
+ .
+ .
+ PERMISSION & CONDITIONS
+ .
+ Permission is hereby granted, free of charge, to any person obtaining a
+ copy of the Font Software, to use, study, copy, merge, embed, modify,
+ redistribute, and sell modified and unmodified copies of the Font
+ Software, subject to the following conditions:
+ .
+ 1) Neither the Font Software nor any of its individual components,in
+    Original or Modified Versions, may be sold by itself.
+ .
+ 2) Original or Modified Versions of the Font Software may be bundled,
+    redistributed and/or sold with any software, provided that each copy
+    contains the above copyright notice and this license. These can be
+    included either as stand-alone text files, human-readable headers or
+    in the appropriate machine-readable metadata fields within text or
+    binary files as long as those fields can be easily viewed by the user.
+ .
+ 3) No Modified Version of the Font Software may use the Reserved Font
+    Name(s) unless explicit written permission is granted by the
+    corresponding Copyright Holder. This restriction only applies to the
+    primary font name as presented to the users.
+ .
+ 4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
+    Software shall not be used to promote, endorse or advertise any
+    Modified Version, except to acknowledge the contribution(s) of the
+    Copyright Holder(s) and the Author(s) or with their explicit written
+    permission.
+ .
+ 5) The Font Software, modified or unmodified, in part or in whole, must
+    be distributed entirely under this license, and must not be distributed
+    under any other license. The requirement for fonts to remain under
+    this license does not apply to any document created using the Font
+    Software.
+ .
+ .
+ .
+ TERMINATION
+ This license becomes null and void if any of the above conditions are not met.
+ .
+ .
+ .
+ DISCLAIMER
+ THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
+ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
+ OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT.  IN NO EVENT SHALL THE
+ COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
+ DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM OTHER
+ DEALINGS IN THE FONT SOFTWARE.
+ .
+
+Files: debian/*
+Copyright:
+ 2008 Alan Baghumian <alan@technotux.org>
+ 2008-2018 Holger Levsen <holger@debian.org>
+ 2009-2012 Christian Perrier <bubulle@debian.org>
+ 2011-2023 Fabian Greffrath <fabian@debian.org>
+ 2018 Rene Engelhard <rene@debian.org>
+License: GPL-2+
+ This package is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 2 of the License, or
+ (at your option) any later version.
+ .
+ This package is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ GNU General Public License for more details.
+ .
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see <https://www.gnu.org/licenses/>
+ .
+ On Debian systems, the complete text of the GNU General
+ Public License version 2 can be found in "/usr/share/common-licenses/GPL-2".

src/correctionInvoicePdf.tsx

@@ -3,6 +3,7 @@ import { Document, Page, View, Text, Image, StyleSheet, renderToBuffer } from "@
 import { formatPrice, formatDate } from "./formatters";
 import { computeTaxBreakdown } from "./taxBreakdown";
 import type { InvoiceSeller } from "./seller";
+import "./fonts";
 
 export type { InvoiceSeller };
 
@@ -29,15 +30,15 @@ export type { InvoiceSeller };
 //   simplest defensible policy — no attempt to re-split a percent/fixed
 //   discount across a partial return).
 //
-// Built-in Helvetica, not a registered web font — same reasoning as
-// invoicePdf.tsx.
+// Liberation Sans (registered by the "./fonts" import above), not built-in
+// Helvetica — same reasoning as invoicePdf.tsx.
 const BRAND = "#f6a701";
 const TEXT_MUTED = "#6b6b69";
 const BORDER = "#e5e0d8";
 const BG_MUTED = "#f8f5f1";
 
 const styles = StyleSheet.create({
-  page: { padding: 0, fontSize: 10, fontFamily: "Helvetica", color: "#1a1a18" },
+  page: { padding: 0, fontSize: 10, fontFamily: "Liberation Sans", color: "#1a1a18" },
   // A rule, not a filled band — a bold brand-colored line rather than a
   // plain 1pt gray divider.
   headerBand: {
@@ -49,8 +50,8 @@ const styles = StyleSheet.create({
     borderBottomWidth: 3,
     borderBottomColor: BRAND,
   },
-  wordmark: { fontFamily: "Helvetica-Bold", fontSize: 14 },
-  kindLabel: { fontFamily: "Helvetica-Bold", fontSize: 22, color: BRAND, letterSpacing: 1 },
+  wordmark: { fontFamily: "Liberation Sans", fontWeight: "bold", fontSize: 14 },
+  kindLabel: { fontFamily: "Liberation Sans", fontWeight: "bold", fontSize: 22, color: BRAND, letterSpacing: 1 },
   body: { padding: 32, paddingBottom: 90 },
   refLine: { fontSize: 10, color: TEXT_MUTED, marginBottom: 24 },
   addressRow: { flexDirection: "row", justifyContent: "space-between", marginBottom: 24 },
@@ -60,7 +61,7 @@ const styles = StyleSheet.create({
   metaRow: { flexDirection: "row", gap: 10, marginBottom: 24 },
   metaBox: { borderWidth: 1, borderColor: BORDER, borderRadius: 6, paddingVertical: 8, paddingHorizontal: 12 },
   metaLabel: { fontSize: 7, color: TEXT_MUTED, textTransform: "uppercase", marginBottom: 2 },
-  metaValue: { fontSize: 10, fontFamily: "Helvetica-Bold" },
+  metaValue: { fontSize: 10, fontFamily: "Liberation Sans", fontWeight: "bold" },
   table: { borderRadius: 6, overflow: "hidden", borderWidth: 1, borderColor: BORDER, marginBottom: 16 },
   tableHeader: { flexDirection: "row", backgroundColor: BG_MUTED, paddingVertical: 8, paddingHorizontal: 10 },
   // Same uniform tinted-row background as invoicePdf.tsx now — no more
@@ -82,8 +83,8 @@ const styles = StyleSheet.create({
   summaryLabel: { fontSize: 10, color: TEXT_MUTED },
   summaryValue: { fontSize: 10 },
   grandTotalRow: { flexDirection: "row", justifyContent: "space-between", paddingTop: 8, marginTop: 6, borderTopWidth: 1, borderTopColor: BORDER },
-  grandTotalLabel: { fontSize: 12, fontFamily: "Helvetica-Bold" },
-  grandTotalValue: { fontSize: 12, fontFamily: "Helvetica-Bold" },
+  grandTotalLabel: { fontSize: 12, fontFamily: "Liberation Sans", fontWeight: "bold" },
+  grandTotalValue: { fontSize: 12, fontFamily: "Liberation Sans", fontWeight: "bold" },
   // Netto, right under Gesamt — same as invoicePdf.tsx's own row.
   nettoRow: { flexDirection: "row", justifyContent: "space-between", paddingVertical: 2, marginTop: 6 },
   // Same "enthält X% MwSt." annotation-under-Gesamt framing as

src/fonts.ts

@@ -0,0 +1,21 @@
+import { Font } from "@react-pdf/renderer";
+
+// Registered once here (not inline in invoicePdf.tsx/correctionInvoicePdf.tsx)
+// and imported by both for its side effect — avoids double-registering the
+// same family when renderEInvoice.ts imports both PDF modules in the same
+// process.
+//
+// Liberation Sans, not built-in Helvetica: PDF/A-3 (required by the
+// Factur-X/ZUGFeRD pipeline in src/einvoice/) has no exemption for the
+// standard/base-14 fonts react-pdf ships — every font actually used must be
+// embedded, and react-pdf only embeds fonts it has real font-file bytes for
+// via Font.register. Liberation Sans is metrically identical to Helvetica/
+// Arial (SIL Open Font License, see src/assets/fonts/LICENSE-OFL.txt), so
+// embedding it doesn't shift any existing layout.
+Font.register({
+  family: "Liberation Sans",
+  fonts: [
+    { src: new URL("./assets/fonts/LiberationSans-Regular.ttf", import.meta.url).pathname, fontWeight: "normal" },
+    { src: new URL("./assets/fonts/LiberationSans-Bold.ttf", import.meta.url).pathname, fontWeight: "bold" },
+  ],
+});

src/invoicePdf.tsx

@@ -3,6 +3,7 @@ import { Document, Page, View, Text, Image, StyleSheet, renderToBuffer } from "@
 import { formatPrice, formatDate } from "./formatters";
 import { computeTaxBreakdown } from "./taxBreakdown";
 import type { InvoiceSeller } from "./seller";
+import "./fonts";
 
 export type { InvoiceSeller };
 
@@ -11,9 +12,10 @@ export type { InvoiceSeller };
 // same render call both times, so a re-download always matches what was
 // emailed.
 //
-// Built-in Helvetica, not a registered web font — this can render inside a
-// fire-and-forget email step; a font-fetch failure there is one more way
-// to lose the invoice attachment for no real design benefit.
+// Liberation Sans (registered by the "./fonts" import above), not built-in
+// Helvetica — PDF/A-3 requires every font actually used to be embedded, and
+// there's no exemption for react-pdf's standard/base-14 fonts. See
+// fonts.ts's own comment for the full reasoning.
 const BRAND = "#f6a701";
 const TEXT_MUTED = "#6b6b69";
 const BORDER = "#e5e0d8";
@@ -21,7 +23,7 @@ const BG_MUTED = "#f8f5f1";
 const SUCCESS = "#2f8f4e";
 
 const styles = StyleSheet.create({
-  page: { padding: 0, fontSize: 10, fontFamily: "Helvetica", color: "#1a1a18" },
+  page: { padding: 0, fontSize: 10, fontFamily: "Liberation Sans", color: "#1a1a18" },
   // A rule, not a filled band — a bold brand-colored line with a thin
   // muted second line underneath, rather than a plain 1pt gray divider.
   headerBand: {
@@ -34,8 +36,8 @@ const styles = StyleSheet.create({
     borderBottomColor: BRAND,
   },
   headerRuleThin: { height: 1, backgroundColor: BORDER, marginHorizontal: 32 },
-  wordmark: { fontFamily: "Helvetica-Bold", fontSize: 14 },
-  kindLabel: { fontFamily: "Helvetica-Bold", fontSize: 22, color: BRAND, letterSpacing: 1 },
+  wordmark: { fontFamily: "Liberation Sans", fontWeight: "bold", fontSize: 14 },
+  kindLabel: { fontFamily: "Liberation Sans", fontWeight: "bold", fontSize: 22, color: BRAND, letterSpacing: 1 },
   body: { padding: 32, paddingBottom: 90 },
   addressRow: { flexDirection: "row", flexWrap: "wrap", justifyContent: "space-between", rowGap: 12, marginBottom: 24 },
   addressBlock: { width: "45%" },
@@ -48,8 +50,8 @@ const styles = StyleSheet.create({
   metaRow: { flexDirection: "row", gap: 10, marginBottom: 16, flexWrap: "wrap" },
   metaBox: { borderWidth: 1, borderColor: BORDER, borderRadius: 6, paddingVertical: 8, paddingHorizontal: 12 },
   metaLabel: { fontSize: 7, color: TEXT_MUTED, textTransform: "uppercase", marginBottom: 2 },
-  metaValue: { fontSize: 10, fontFamily: "Helvetica-Bold" },
-  paidBadgeText: { fontSize: 10, fontFamily: "Helvetica-Bold", color: SUCCESS },
+  metaValue: { fontSize: 10, fontFamily: "Liberation Sans", fontWeight: "bold" },
+  paidBadgeText: { fontSize: 10, fontFamily: "Liberation Sans", fontWeight: "bold", color: SUCCESS },
   // Same plain-text treatment as paidBadgeText (no pill/box, see that
   // style's own comment) — muted, not an error/warning color, since an
   // unpaid Vorkasse invoice isn't a problem, just a pending, expected
@@ -98,8 +100,8 @@ const styles = StyleSheet.create({
   summaryLabel: { fontSize: 10, color: TEXT_MUTED },
   summaryValue: { fontSize: 10 },
   grandTotalRow: { flexDirection: "row", justifyContent: "space-between", paddingTop: 8, marginTop: 6, borderTopWidth: 1, borderTopColor: BORDER },
-  grandTotalLabel: { fontSize: 12, fontFamily: "Helvetica-Bold" },
-  grandTotalValue: { fontSize: 12, fontFamily: "Helvetica-Bold" },
+  grandTotalLabel: { fontSize: 12, fontFamily: "Liberation Sans", fontWeight: "bold" },
+  grandTotalValue: { fontSize: 12, fontFamily: "Liberation Sans", fontWeight: "bold" },
   // Netto, right under Gesamt — a bit of top margin to read as its own
   // line following the total, not crowded against the divider above it.
   nettoRow: { flexDirection: "row", justifyContent: "space-between", paddingVertical: 2, marginTop: 6 },