PDF Invoices and Packing Slips

What it does

Generates a real PDF invoice and (optionally) a packing slip for every WooCommerce order. Customers download from the My Account → Orders list, the single-order detail page, or a button injected into the order confirmation email. Admins get a dedicated PDF column on the orders list (HPOS and legacy), a per-order metabox for invoice number overrides and per-order notes, and bulk-print actions that combine many orders into one multi-page PDF with page breaks between them. PDFs can also be auto-attached to the Completed, Processing, Manual Invoice, and Refunded customer emails as real .pdf attachments.

Numbering is sequential and gap-free using an atomic SQL counter (race-condition safe), with prefix and zero-padding controls. If the Sequential Order Numbers module is active, invoice numbers stay aligned with the order number. Rendering is handled by Dompdf via Asteris\Core\PDF_Generator; if Dompdf is unavailable, the module falls back to a printable HTML page so the feature degrades gracefully. This module replaces WP Overnight PDF Invoices Premium ($79/yr) and WooCommerce PDF Invoices by Skyverge ($79/yr).

Quick start

1. Activate the PDF Invoices and Packing Slips module from Asteris → Dashboard.
2. Go to Asteris → PDF Invoices and pick one of the five designs (Modern, Classic, Minimal, Branded, Compact).
3. Fill in Company details (name, address, Tax ID / ABN / VAT, email, phone, website) and upload your Logo.
4. Set your Number prefix (e.g. INV-), Starting number (default 1001), and Number padding (default 4).
5. Under PDF email attachments, tick the WooCommerce emails you want the PDF auto-attached to. The Completed email is on by default.
6. Save settings, then open any order in WooCommerce and click View Invoice in the order data box, or click the PDF icon on the orders list.

Settings reference

All options are stored under the prefix asteris_pdf_invoices_* (one update_option per field, BOM-free admin-post.php save handler — not Settings API).

Setting	What it does	Default	Valid values
template	Design used for invoice and packing slip output	modern	modern, classic, minimal, branded, compact
doc_title_invoice	Header title on invoice documents	Tax Invoice	Any string
doc_title_packing	Header title on packing slip documents	Packing Slip	Any string
company_name	Company name printed in the header	Site name	Any string
company_address	Multi-line address block	Empty	Multi-line string
company_tax_id	ABN / VAT / Tax ID line	Empty	Any string
company_email	Contact email shown on the document	admin_email	Valid email
company_phone	Contact phone number	Empty	Any string
company_website	URL shown on the document	home_url()	Valid URL
logo_id	WP attachment ID of the logo (embedded as base64 data URI for reliable Dompdf rendering)	0	Positive integer
accent_color	Hex colour for headings, totals, and the customer email button	#1a3a6c	Hex colour
footer_text	Footer line on every invoice	Thank you for your order!	Multi-line string
show_packing	Show the Packing Slip button on admin order screens	1	0 / 1
packing_show_notes	Include customer notes on the packing slip	1	0 / 1
invoice_prefix	Prefix before the invoice number	INV-	Any string
invoice_start_number	First sequential invoice number	1001	Positive integer
invoice_padding	Zero-pad width of the number portion (4 → 0001)	4	0-10
date_format	PHP date format for dates on the document. Empty = WordPress site default	Empty	Any date() format
show_generated_on	Show the “Generated on” timestamp in the footer	1	0 / 1
attach_completed	Attach PDF to Customer Completed Order email	1	0 / 1
attach_processing	Attach PDF to Customer Processing Order email	0	0 / 1
attach_invoice_mail	Attach PDF to Customer Invoice email	1	0 / 1
attach_refunded	Attach PDF to Customer Refunded Order email	0	0 / 1

Per-order overrides (set on the order edit screen, stored as order meta):

Meta key	What it does
_asteris_invoice_number	Locks a specific number to the order (blank = auto-assign on first generation)
_asteris_invoice_note	Per-order note printed bottom-left of the invoice (independent of the global footer)

Common workflows

Issuing a tax invoice for an Australian GST-registered store

1. Open Asteris → PDF Invoices.
2. Set Invoice title to Tax Invoice (required wording under ATO rules for GST-registered businesses).
3. Enter your ABN under Tax ID / ABN / VAT.
4. Choose the Classic or Modern template — both present totals and GST lines cleanly.
5. Tick Attach PDF to Order Completed email.
6. Place a test order, mark it Completed, and confirm the customer receives the PDF attached to their email.

Bulk-printing packing slips for the warehouse

1. Go to WooCommerce → Orders (works on both HPOS and legacy screens).
2. Tick the orders you want to ship.
3. From the Bulk actions dropdown, choose Print packing slips and click Apply.
4. A new tab opens with a single multi-page PDF — one packing slip per order, page-break-separated.
5. Print from your browser. The nonce expires after one minute and the URL is one-time use per session.

Overriding the invoice number on a specific order

1. Open the order in WooCommerce.
2. In the right-hand sidebar, find the Asteris — Invoice metabox.
3. Type a number into Override the invoice number. Leave blank to let the auto-counter take over.
4. Save the order. The override is stored in _asteris_invoice_number and survives regeneration.

Adding a per-order note (e.g. payment terms)

1. Open the order edit screen.
2. In the Asteris — Invoice metabox, fill the Invoice note textarea (e.g. Payment due within 14 days).
3. Save. The note appears in the bottom-left of the rendered invoice, independent of the global footer text.

Customising a template

1. Copy the desired template from wp-content/plugins/asteris-for-woocommerce/src/Modules/PDF_Invoices/Templates/{template}.php.
2. Paste it to wp-content/themes/{your-theme}/asteris/pdf-invoices/{template}.php.
3. Edit freely — the helper.php template loader picks up theme overrides automatically.
4. Theme overrides survive plugin updates.

Debugging template output

1. Append &debug=html to any invoice URL (e.g. /?asteris_invoice=ORDER_KEY&type=invoice&debug=html).
2. The module returns the raw HTML instead of streaming a PDF, including an HTML comment identifying the active template ID.
3. Use this to inspect CSS rendering issues before Dompdf converts the HTML.

For developers

Stability commitment. Hooks, filters, REST endpoints, and shortcodes documented below follow semver. Breaking changes happen only on major version bumps, with at least one minor version of deprecation notice in advance. Anything not listed here (internal AJAX handlers, settings save handlers, internal plumbing hooks) is implementation detail — those may change without notice.

This module does not yet expose any custom asteris_* filters, actions, shortcodes, or REST endpoints. The integration points below are public-facing but are not extension hooks:

URL pattern

Public render endpoint (hooked on init):

/?asteris_invoice={order_key}&type={invoice|packing-slip}

Authentication is by WooCommerce order key — the same token used in customer order emails. Admin bulk print uses asteris_invoice=multi with keys=KEY1,KEY2,... and a _wpnonce for the asteris_bulk_invoices action; requires manage_woocommerce capability.

Theme template override path

wp-content/themes/{your-theme}/asteris/pdf-invoices/{template}.php

Where {template} is one of modern, classic, minimal, branded, compact. Theme overrides are a committed extension point and survive plugin updates.

Troubleshooting

”Invoice not found” 404 when clicking the download link

The URL uses the WooCommerce order key as its security token (wc_get_order_id_by_order_key). If the order has been deleted, the key has been regenerated, or the link was sent before an order key reset, the lookup fails. Resend the order confirmation email from the order edit screen to issue a fresh URL.

PDF is served as HTML instead of a true PDF

The module checks Asteris\Core\PDF_Generator::is_available() before streaming. If Dompdf cannot be loaded (PHP mbstring or gd missing, server memory limit too low for the bundled library), the fallback is an HTML page printed in-browser. Check Tools → Site Health for missing PHP extensions and raise WP_MEMORY_LIMIT to at least 256M.

Logo missing from the rendered PDF

The module embeds the logo as a base64 data URI by reading the attachment file directly with file_get_contents(). If the attachment file has been moved off disk (e.g. offloaded to S3 with no local copy), the embed fails and the module falls back to the attachment URL — which Dompdf may not be able to fetch over HTTPS. Re-upload the logo or keep a local copy.

Bulk print returns “Permission denied” or “Invalid request”

Bulk print requires the manage_woocommerce capability and a valid asteris_bulk_invoices nonce. The transient that carries the multi-print URL expires after MINUTE_IN_SECONDS (60s). If you wait too long between clicking the bulk action and the new tab opening, retrigger the bulk action.

Invoice numbers skip or duplicate

The counter is incremented via an atomic UPDATE … SET option_value = option_value + 1 on wp_options. Skips can happen if you manually edit the asteris_pdf_invoices_next_number option, restore a database backup, or assign a manual override that collides with the auto sequence. Use the per-order Override the invoice number field to repair gaps; the override is locked into _asteris_invoice_number and won’t be recycled.

Known plugin conflicts

• WP Overnight PDF Invoices, WooCommerce PDF Invoices by Skyverge, and similar — both this module and theirs hook woocommerce_email_attachments. Deactivate the other plugin to avoid duplicate PDF attachments on customer emails.
• Caching plugins (WP Rocket, W3 Total Cache, LiteSpeed) — the invoice URL is dynamic (?asteris_invoice=...) but contains a query string that some aggressive setups still cache. Add asteris_invoice to the cache exclusion query-string list.
• Custom Order Numbers plugins (other than Asteris Sequential Order Numbers) — the module reads _asteris_order_number to keep invoice numbering aligned. Third-party order-number plugins store under different meta keys, so the invoice counter will run independently from your order numbers. No data loss, but the two sequences will diverge.
• Other compatibility conjectural until reported — submit issues at the support forum if you hit a conflict.

What is in Free vs Paid

A reduced lite version ships in Asteris Free. The full module is paid-tier only.

Free (lite):

• 1 plain template
• Customer-only download from the order page

Paid (Pro, Agency, Founder Lifetime) adds:

• All 5 designs (Modern, Classic, Minimal, Branded, Compact)
• Auto-attach PDFs to WooCommerce customer emails (Completed, Processing, Manual Invoice, Refunded)
• Branding controls (logo, accent colour, custom footer, per-order notes)
• Packing slips with optional customer notes
• Credit notes for refunded orders
• Bulk admin print (combined multi-page PDF)
• Sequential, gap-free invoice numbering with prefix and padding
• WP Overnight migration adapter

Related

• Sequential Order Numbers module — keeps invoice numbers aligned with order numbers
• Migrating from WP Overnight PDF Invoices
• Pricing and tiers
• Compatibility matrix
• Theme template overrides — general guide

Changelog

Version	Date	Notes
1.9.7	2026-06-01	Documented in detail. Previous entries in plugin changelog.