Web Invoice - Invoicing and billing for WordPress

It also handles recurring billing, for tedious monthly (periodically) payments.

The plugin ties into WP's user management database to keep track of clients and their information.

Credit card payments may be accepted via Authorize.net, MerchantPlus' NaviGate, Moneybookers, AlertPay, Google Checkout or PayPal accounts.

Installation:

Unpack and upload it to the /wp-content/plugins/ directory.
Activate the plugin through the 'Plugins' menu in WordPress.

Features:

• General features:
• Create invoices from the WordPress control panel
• Prefill customer information using the WordPress user list
• Download invoice as PDF document
• Send invoice notifications to customers with a secured link back to the web invoice
• Send invoice reminders to customers with a secured link back to the web invoice
• Accept credit card payment via PayPal Payflow, Authorize.net, Sage Pay or MerchantPlus NaviGate
• Moneybookers, AlertPay, Google Checkout or PayPal available if you don't have a credit card processing account
• Setup recurring billing using Authorize.net's ARB (Automatic Recurring Billing) feature, Google Checkout Subscriptions, PayPal, AlertPay or Moneybookers
• Force web invoice pages to be viewed in SSL mode
• Archive old invoices
• Easily use old invoices as templates for new ones
• Dynamic and intuitive user interface
• Automatically mark invoices paid via Moneybookers (Requires merchant status), AlertPay (Requires merchant status), PayPal, Payflow, Payflow Pro, Sage Pay, Authorize.net or Google Checkout as paid
• Split gateway support (Your client is given the option of choosing the preferred gateway from the list of gateways you support). e.g PayPal and Moneybookers
• All user interfaces are internationalized
• E-mail templates and hooks to allow you to customize the e-mails sent to your clients
• Integrate with other plugins, actions available: web_invoice_mark_as_paid, web_invoice_content_append, web_invoice_front_top, web_invoice_front_bottom, web_invoice_front_top, web_invoice_front_paid, web_invoice_front_unpaid, web_invoice_invoice_save, web_invoice_process_settings, web_invoice_display_settings, web_invoice_invoice_restart_recurring, web_invoice_invoice_pause_recurring
• Works with WordPress 3.x and WPMU 3.x
• Google Checkout support
• Google Checkout subscriptions and PayPal Payflow support
• Sage Pay support
• AlertPay subscriptions support
• Languages:
• Italian (it_IT)
• Belarusian (be_BY)
• Portugese (pt_BR)
• Spanish (es_ES)
• Swedish (sv_SE)
• French (fr_FR)

What is new in this release:

• Currency CHF added.
• due_date added as a template variable.
• Use date_format option when available.
• Fixed issue 36: separating customizations from core file.
• Added a link to report missing currencies.
• Fixed PayPal IPN.
• Multi site network activate fix.
• New logo.

What is new in version 2.0.22:

• Added missing address in the shipping info in the user profile.
• Prevent checking archived invoices when check all is clicked.

What is new in version 2.0.10:

• Moneybookers subscriptions fail.

What is new in version 2.0.8:

• Fixed issue 26: "Same As Billing" does not copy country.
• Fixed issue 27: "Tax" field seems to have control characters in it. e.g. "s:4:" or "s:0:".
• Fixed issue 28: Web/HTML Invoice Template.
• Fixed issue 29: Tabbed settings and templates page.
• Fixed issue 31: Per invoice payment options.
• Support payments via 2Checkout.
• Fixed issue 9: Partial payments on an invoice.

What is new in version 2.0.5:

• Fixed issue: Invalid argument supplied for foreach().

Requirements:

• WordPress 2.6 or higher