---
title: PostalForm postcards
description: PostalForm supports a browser postcard template catalog and custom PDF postcards through its machine-order API. Postcards are not limited to API access. The browser flow collects the names and message, creates a preview, and continues to order review. Custom artwork follows the PDF requirements below.
seotitle: "PostalForm postcards: browser templates and API PDF requirements"
seo-description: Create a postcard with a PostalForm browser template or submit a two-page PDF through the API. Compare sizes, artwork requirements, addresses and proof options.
group: resources
indexable: true
nav: false
schema: webpage
eyebrow: Postcards
published: 2026-10-15
updated: 2026-10-15
path: /postcards
---
# PostalForm postcards

PostalForm supports a browser postcard template catalog and custom PDF postcards through its machine-order API. Postcards are not limited to API access. The browser flow collects the names and message, creates a preview, and continues to order review. Custom artwork follows the PDF requirements below.

## How can an agent send a postcard?
PostalForm accepts a two-page postcard PDF through its machine-order endpoints. The agent supplies the artwork, size, buyer and address fields, validates the document, and presents the quoted price before payment. PostalForm adds mailing information and routes eligible postcards to a print provider; postcards do not support Certified Mail.

## Choose a postcard workflow
| Workflow               | Use when                                              | Required input                                    | Review                                       |
| ---------------------- | ----------------------------------------------------- | ------------------------------------------------- | -------------------------------------------- |
| Browser template       | You want a ready-made design                          | Recipient name, sender name and message           | Generated front/back preview before checkout |
| Custom PDF through API | You already have finished artwork                     | Two-page PDF, supported size, buyer and addresses | Validate the layout and quote before payment |
| Letter instead         | You need private enclosed documents or Certified Mail | Letter text or document                           | [Send a letter](/send-letter-online)         |

## PDF sizes and layout
| `postcard_size` | Trim size     | Required PDF canvas on both pages |
| --------------- | ------------- | --------------------------------- |
| `4x6`           | 6 × 4 inches  | 6.25 × 4.25 inches                |
| `6x9`           | 9 × 6 inches  | 9.25 × 6.25 inches                |
| `11x6`          | 11 × 6 inches | 11.25 × 6.25 inches               |

Page 1 is the artwork side. Page 2 is the mailing side. Keep the reserved mailing block clear; provide sender and recipient information in the order fields rather than drawing addresses, indicia or barcodes into the PDF. A postcard must have exactly two PDF pages using the selected bleed canvas. See the [PDF guidelines and downloadable templates](/postcard-pdf-guidelines).

## Machine request
Use the full buyer and address envelope in the [machine order guide](/agents). Set these document properties:

```json
{
  "mailpiece_type": "postcard",
  "postcard_size": "4x6",
  "pdf": "https://your-public-file-host.example/postcard.pdf"
}
```

This is a document fragment, not a complete order. `letter` and `form` are not supported as postcard sources. Postcards print in color on both sides. Do not request Certified Mail, Return Receipt or letter-only delivery upgrades. Eligibility and the returned quote determine the available service.

Validate the complete body at `POST /api/machine/orders/validate` for x402 or `POST /api/machine/mpp/orders/validate` for MPP. The create paths are `/api/machine/orders` and `/api/machine/mpp/orders`. A payment challenge is not a successful mailing; pay only with owner authorization, retain the request ID on retries, and verify the order status afterward.

## Destination and pricing rules
PostalForm chooses a provider using destination, sender, size and availability. The Lob international route supports only `4x6` postcards with a U.S. return address. Other destinations and larger sizes require an eligible route; an accepted template size does not guarantee every destination. Validate the actual addresses and document before promising a price or delivery date.


## Resources
- [Browser postcard templates](/postcards)
- [Exact PDF layout guidelines](/postcard-pdf-guidelines)
- [Machine ordering and payment](/agents)
- [Official agent integrations](/agent-integrations)
- [Mailing limits and routing](/mailing-limits)
- [Pricing](/pricing)