Postal API – Letter API and Postcard API

Send postal letters and postcards (snail-mail) using our SOAP-based Web Services API

For the technically advanced, we provide the ability to integrate your application or service to our Postal API. We provide code samples to many different applications.  Developers may integrate their applications and service to the PostalMethods Software-as-a-Service (“SaaS”) Postal-API and send postal mail digitally.  Below is all the information you need to develop your API.

Developer Quick Start Guide
(View/Download PDF)
Below is all the information you need to get started creating your own API.  If you need assistance, we have partners that can help you to build your API.
Reference Manual
The formal, official repository of all PostalMethods definitions.
(View/Download PDF)
Postal Web Service: See this document for a full explanation of methods and properties used to send letters and postcards, get statuses, cancel delivery and more, using the PostalMethods Web Service.
SOAP Method Reference:  See this document for the methods available for submitting messages to the PostalMethods service via SOAP XML.
Email Reference:  See this document for a full explanation on how to send letters using email messages.
Push Feedback:  Learn how to receive automatic feedback from PostalMethods upon updates to your mail items’s status.  Feedback messages may be sent by email or by SOAP XML and HTTP POST.
Administrative Web Service:  These are OPTIONAL, advanced methods which allow management of user accounts. They are NOT necessary for regular mailing of documents.
Status and Error Codes:  See a full list of possible status and error codes and related explanations.
Supported File types:  See a list of documents and file types supported by PostalMethods.
Development Requirements:  Required conditions needed to integrate with the PostalMethods Postal API.
System Limitations:  General System limitations and thresholds
Appendices:  USPS -Specific Instructions on Constructing Your Address Book and Stationery Sizes, Margins, and Clearzones.
Code Samples:  Demonstrating how to use PostalMethods’ various Web Service methods from a variety of development environments, such as .NET (VB.NET and C#), PHP, and even ASP.

Features & Benefits

  • No Hardware – No need to worry about printers, folding and inserting machines, metering equipment and hardware maintenance. Save expensive electricity and valuable office space.
  • No Software – No need to worry about presorting software and address verification (CASS, DPV and NCOA). Be up and running in minutes.
  • No Perishables – No need to worry about ink cartridges, paper stocks, envelopes and stamps.
  • Unlimited Scalability – Whether you need to send one letter or ten thousand, our servers get the job done.
  • Full Control – Web-based administration screens allow you to monitor activity and control settings.
  • Better health – Avoid poisoning due to stamps licking…

Sample Uses

  • Invoicing – Mail invoices and order confirmations directly from order processing systems.
  • Marketing – Send colorful postcards immediately after a successful sales meeting.
  • Healthcare – Mail your patients their test results immediately when they are ready.
  • Accounting – Automatically send past-due payment notes.
  • Property Management – Send rent payment letter reminders and postcard alerts.
  • Regulatory – Comply with regulatory acts and automatically send mandatory notification letters such as the Occupational Safety and Health Administration (OSHA) and similar.
Send Letters
Securely + Reliably
Send letters securely and reliably from any business application. Use for invoices, quotes, and other important business communications. Enjoy special web-form to postal features and instant notifications.
Simple Process
Easy as 1-2-3
Experience the ease of our streamlined process - developed for efficiency! You submit your document by email or API. We automatically print, collate, insert, and stamp your letter. Your letter is delivered via standard postal service.
Pay As You Go
No Fuss. No Obligations.
Register for free with no obligations! Evaluate the service as long as you need. Once you are ready, set up our user-friendly pay-as-you option to use our service. No fuss. No on-going commitment. Just plain easy!