Our API directory now includes 35 invoicing APIs. The newest is the CashFlows API. The most popular, in terms of mashups, is the PayPal API. We list 33 PayPal mashups. Below you'll find some more stats from the directory, including the entire list of invoicing APIs.
In terms of the technical details, REST and XML lead the way. There are 28 invoicing REST APIs and 6 invoicing SOAP APIs. Our directory lists 30 invoicing XML APIs and 17 invoicing JSON APIs.
The most common tags within invoicing are 14 enterprise invoicing APIs, 13 finance invoicing APIs and 10 billing invoicing APIs
On the mashup side, we list 5 invoicing mashups. We named Mobile Time Tracking as mashup of the day in August.
For reference, here is a list of all 35 invoicing APIs.
1DayLater API: Business expense tracking tool
ActiveCollab API: Collaboration & Project Management System
billFLO Seller API: Invoice management service
billomat API: Online billing service
Blesta API: Billing Service
Blinksale API: Online invoicing services
Bunker App API: Project management Platform
Cashboard API: Financial and time tracking service
CashFlows API: Web and mobile payment platform
ClientBill API: Online invoicing service
CurdBee API: Online billing software
e-conomic API: Online accounting software
entreprise-facile API: Create entreprise-facile automations and mashups
fetchflow API: Online invoicing and payment service
FreshBooks API: Online invoicing and time tracking
Greendizer API: Invoicing designed for developers
Invoice Machine API: Invoice management service
InvoiceClarity API: Invoice management service
Invoicefu API: Online invoicing service
Invoicera API: Invoicing & Billing Service
Klarna API: eCommerce service
Less Accounting API: Online accounting service
Maventa e-invoicing API: Electronic invoicing services
MoneyBird API: Online billing service
Ofuz API: Customer management and invoicing service
PayPal API: Online payments
PayPal Invoicing API: PayPal Invoicing APIs
Seasoo API: Online invoicing service
ServiceM8 API: Service job management service
serviceminder API: Service provider online solution service
Stripe API: Online payment service
Tradeshift API: Business Network and Invoice management service
WorkflowMax API: Job and Invoice Management
Xero API: Online accounting service for SMBs
Zoho Invoice API: Online invoicing service
