USPS PC Postage Services
A PC Postage Service is a product supplied by a PC Postage Provider to generate prepaid, electronic postage for use with the United States Postal Service (USPS). There are several PC Postage Services available, and some are free while others require a monthly service fee or other fees. The below table only contains information for the PC Postage Services that are free. This table is designed to provide a reference on which mailing services and features are available with which PC Postage Service. This article is geared toward single-item retail rates and does not address any bulk mail products from USPS.
PC Postage Services Introdution 
USPS Click-N-Ship 
USPS Click-N-Ship is offered free at USPS.com for any registered user. Only Priority Mail and Express Mail products are supported. There is no stealth postage, and only laser/inkjet printers are supported; dedicated label printers are not supported. Click-N-Ship does not require Java or any plugins - only Adobe Acrobat Reader is required for printing. Sample labels can be generated, but only for Priority Mail (domestic) or Express Mail International. Click-N-Ship supports the USPS SCAN Form (PS Form 5630) for bulk acceptance scans. Date correction indicia are not available. Unused postage can be voided within 10 days of purchase. All labels require the use of e/Delivery Confirmation service.
PayPal Ship Now 
PayPal Ship Now is a service provided to registered users of the PayPal payment service. PayPal offers a "Ship Now" link on the transaction details page for any Goods payment received, and the address supplied by the buyer will be pre-populated. Labels can also be created to any address by bookmarking the PayPal Ship Now URL. PayPal supports several thermal label printers, for domestic shipments only, in addition to the standard laser/inkjet printer support. Neither Adobe Acrobat Reader nor Java are required for domestic laser/inkjet labels (PayPal uses an invisible frame with a GIF image); however, Java is required to print international labels or domestic labels on a thermal label printer. Sample labels are not available, nor are date correction indicia. Unused postage can be voided within 2 days of purchase. Stealth postage is available. All labels require the use of e/Delivery Confirmation service.
PayPal MultiOrder Shipping 
PayPal MultiOrder Shipping (abbreviated MOS) is another service provided to registered users of the PayPal payment service. The MOS tool can be opened from the overview page after logging in to PayPal. MOS will present a list of recent payments received in PayPal, and also allow you to manually create a label to any address.
MOS does not support any international shipments. MOS supports the same thermal label printers as PayPal Ship Now, and just like Ship Now, Java is required to print labels on a thermal label printer. MOS supports the USPS SCAN Form (PS Form 5630) for bulk acceptance scans. Sample labels are not available, nor are date correction indicia. Unused postage can be voided within 2 days of purchase. Stealth postage is available.
eBay Shipping Label 
eBay's Shipping Label product, released in 2009, allows eBay users to create single labels for orders for items sold on eBay. Multiple labels can be created for one order, and the address can be changed, but all labels created for an eBay order will have the label information forwarded to the eBay item buyer via e-mail and the My eBay page. The label functionality is similar to PayPal Ship Now, but all of the USPS Flat Rate products are available. Thermal label printers are supported, and international shipping is available. There are no sample labels, date correction indicia, or SCAN Forms. Unused postage can be voided within 2 days of purchase.
Dymo Stamps 
Dymo Stamps creates single stamp-like labels. It is only available for owners of certain Dymo LabelWriter series label printers. Postage can be either a single stamp printed from the Dymo LabelWriter, or a sheet of 20 stamps printed on a laser/inkjet printer. Sample labels can be created. Labels are paid from a postage account that is replenished in $10.00 increments. Once a label is printed, it cannot be refunded, even if there is a print error. Delivery Confirmation and other special services are not supported with Dymo Stamps. Dymo Stamps do not bear an expiration date and can be used anytime in the future.
PC Postage Service Matrix 
|USPS Product||PC Postage Service|
|USPS Click-N-Ship||PayPal Ship Now||PayPal MultiOrder Shipping||eBay Shipping Label ||Dymo Stamps|
|Domestic Services||First-Class Mail Letter||No||No||No||No||Yes|
|First-Class Mail Flat||No||No||No||No||Yes|
|First-Class Mail Parcel||No||Yes||Yes||Yes||Yes|
|Priority Mail (Zone, Weight)||Yes||Yes||Yes||Yes||Partial |
|Priority Mail Flat Rate Envelope||Yes||Yes||Yes||Yes||Yes|
|Priority Mail Small Flat Rate Box||Yes||No||No||Yes||Yes|
|Priority Mail Medium Flat Rate Box||Yes||Yes||Yes||Yes||Yes|
|Priority Mail Large Flat Rate Box||Yes||No||No||Yes||Yes|
|Express Mail Flat Rate Envelope||Yes||Yes||Yes||Yes||Yes|
|International Services||First-Class Mail International Letter||No||No||No||No||Partial |
|First-Class Mail International Flat||No||No||No||No||No|
|First-Class Mail International Parcel||No||No||No||No||No|
|Priority Mail International (Group, Weight)||Yes||Yes||No||Yes||No|
|Priority Mail International Flat Rate Envelope||Yes||Yes||No||Yes||No|
|Priority Mail International Small Flat Rate Box||Yes||No||No||Yes||No|
|Priority Mail International Medium Flat Rate Box||Yes||Yes||No||Yes||No|
|Priority Mail International Large Flat Rate Box||Yes||No||No||Yes||No|
|Express Mail International||Yes||Yes||No||Yes||No|
|Express Mail International Flat Rate Envelope||Yes||No||No||Yes||No|
|Other Features||Stealth Postage||No||Yes||Yes||Yes||No|
|e/Delivery Confirmation ||Required||Required||Required||Required||No|
|Thermal Label Printers ||No||Yes||Yes||Yes||Dymo Required|
|Rate Tier||Commercial Base||Commercial Base||Commercial Base||Commercial Base||Retail|
|Refunds available||Before 10 days||Before 2 days||Before 2 days||Before 2 days||No|
- ^ Except, those services which include free tracking service (Priority Mail International, Express Mail, and Express Mail International) will include that service instead of e/Delivery Confirmation.
- ^ eBay Shipping Label can only create labels for items you have sold on eBay.
- ^ Postage can be generated for a 1 lb. Priority Mail item to any zone in the USA.
- ^ Only 1 oz. First Class Mail International Letter is supported.
- ^ International PC Postage cannot be printed on thermal label printers with PayPal or eBay.