How do I connect Square to PigeonTrail?
You connect from the Connections page in PigeonTrail, where the Square card has a Connect Square button once the connection is open for your account. The button takes you to Square, where you sign in to the account your store runs on and see exactly what PigeonTrail asks to do: read your business name and locations, read your orders and update them. When you allow it, Square sends you back to PigeonTrail, and we check that we can read your orders before we save anything.
Square never gives us your Square password. We keep the keys Square gives us encrypted, and we use them only to read your orders and mark the ones you print as shipped.
If the Square card isn't on your Connections page yet, you can still bring Square orders in through ShipStation, which connects to Square, or by typing an order in on the Send page.
How do Square orders get into PigeonTrail?
Press Import from Square on the Orders tab of the Send page, and PigeonTrail brings in each open order in your Square account that is paid and has a shipment still to go out, each one once. It looks across all of your active locations and uses the shipping address on the order. Pickup orders, local delivery orders and orders that are already marked shipped stay out, and an order that isn't paid yet waits until it is, then comes in on a later import. Each address is checked against USPS data before anything prints, and PigeonTrail mails only to addresses in the United States.
You can also let new orders come in by themselves. On the Connections page, tick Automatically pull new orders every 15 minutes on the Square card, and PigeonTrail checks your account every 15 minutes, so the orders are waiting when you sit down to print.
When the buyer chose a tracked shipping option whose name says Priority Mail, Ground Advantage, Media Mail, UPS or FedEx, the order goes straight to a separate Packages list instead of your letters. Orders of $50 or more go there too, with a file you upload to Pirate Ship to buy Ground Advantage labels, and you can change that $50 line in Settings or turn it off. When Pirate Ship's shipments file comes back, each package is marked shipped in Square with its carrier and its real tracking number.
How do I print tracked envelopes?
Pick the orders, choose what to print on and print from your own printer. PigeonTrail prints #10, #9, #6 3/4, A7 and 6 x 9 envelopes, Avery 5163 address sheets, 4 x 2 and 4 x 6 thermal labels, and a window slip that folds into a #10 window envelope. Each one carries the buyer's address and a USPS Intelligent Mail barcode in the places USPS's machines read them, with your return address and, if you like, your logo. You add a Forever stamp, which is $0.82 for a 1 ounce letter, and drop the letters in the mail.
The barcode only gets scanned when the letter goes through USPS's sorting machines, so keep it flat and flexible. Our letter checker tells you whether a mailer counts as a letter, whether it is machinable and how many stamps it needs.
What happens in Square after I print?
Each letter you print marks the shipment on its Square order as completed, with USPS as the carrier and the link to the letter's PigeonTrail tracking page saved where Square keeps a shipment's tracking link. A stamped letter has no carrier tracking number, so the shipment carries none. Square's documentation doesn't say whether Square emails your buyer when an app marks a shipment done this way, so we don't count on Square to send the link.
Square only lets a shipment be marked done once the order is paid, so if an order somehow isn't paid by the time you print, the Orders page says so next to it and you can mark it shipped in Square once the buyer pays. If Square refuses an order for another reason, for example because you canceled it, the Orders page shows that reason too.
What does my buyer see?
Every letter gets a tracking page with your shop's logo and colors, a map of the route so far and the day USPS expects it to arrive. When the Square order carries the buyer's email address, we email your buyer that link at the first USPS scan. If you're on Pro, our emails come from your shop's name, and your buyer hears from you when the letter is mailed, when it's almost there and when USPS marks it delivered.
A letter's scans come from USPS's sorting plants, and its delivered event is USPS's estimate from the carrier's route rather than a scan at the mailbox. Our guide to what each USPS scan means explains what your buyer will see.
What if my Square account also feeds ShipStation?
Connect whichever one you like, or both, and each sale still prints one letter. PigeonTrail matches Square's own order ID, which is unique across Square, so whichever connection brings an order in first keeps it and the other import skips it.
Questions
Will the Square order show a tracking number?
No. A stamped letter has no carrier tracking number, so PigeonTrail marks the shipment complete with USPS as the carrier and the letter's tracking link in place of a number. We never send the barcode as a tracking number, because USPS Tracking shows nothing for it on a stamped letter.
What does PigeonTrail get to do in my Square account?
It reads your business name and your locations, reads your orders, and updates the orders you print so their shipments show as done. It can't take payments, see your customer list or touch your bank details, and it doesn't change your items or your prices.
How do I take PigeonTrail's access away later?
Choose Disconnect on the Connections page, and we ask Square to end our access and forget the keys Square gave us. If you remove PigeonTrail from your Square account first, we disconnect the account on our side as soon as Square tells us, or the next time Square turns us away.
Does PigeonTrail need Square to work?
No. Square is one way in, and you can also connect Shopify, eBay, WooCommerce, BigCommerce, Wix or ShipStation to PigeonTrail directly, or bring in an order file from TCGplayer, Amazon or Etsy.
Sources
- Square Developer, "OAuth API Overview", on how a seller lets an app into their Square account and how long its access lasts, read October 28, 2026: developer.squareup.com
- Square Developer, "Square API Permissions", on which permission each order and location call needs, read October 28, 2026: developer.squareup.com
- Square Developer, "Search Orders", on finding a seller's orders by state and fulfillment, read October 28, 2026: developer.squareup.com
- Square Developer, "Fulfillments", on shipment fulfillments, their states and their carrier and tracking fields, read October 28, 2026: developer.squareup.com
- Square Developer, "Update Order", on changing an open order at its current version, read October 28, 2026: developer.squareup.com
