How to Send Postcards, Start to Finish
Last updated October 27, 2026
Sending is one short flow with four steps: List, Design, When and Pay. Press Send postcards on Home or in the sidebar and you are in it.
Nothing is sent until the last step. Your choices are saved as a draft as you go, so you can close the window and pick up later: Home shows Finish your draft, and so does your Mailings list. Only an account admin can send.
Before you start
You can open the flow with nothing ready and sort things out as it asks. Four things have to be in place by the end:
- A list of people with mailing addresses. Usually an Excel or CSV export from your practice-management or field-service software. See How to Import Contacts from a CSV File.
- A postcard design you have checked. You can upload your own artwork, make one in the Design Studio, or reuse a saved design.
- A return address. It is printed on every card and is where undeliverable mail goes. The Pay step asks for it if you have not set one, right on the page.
- A payment method. Cards are paid from your wallet. If the wallet does not cover the send, Pay charges your card to fill it. See How PostKnock Pricing Works.
Step 1: List
Who is getting it.
There are up to three ways to choose people. Pick whichever matches what you have:
- Upload a list. Drop in a spreadsheet. We match the columns (name, address, phone) for you and show a preview before anything is added. If some of the people are already in your account, you choose whether to skip them, update them, or import anyway.
- Pick from contacts. Tick the people you want, or use Everyone with a full address to take the whole account in one click. Filters (list, tag, date added) narrow it down.
- Find a list. Choose ZIP codes, see how many households match for free, then buy the addresses from your wallet. This tab shows when buying a list is available for your account.
Before you continue you see how many people will get a card. People with no full mailing address, and anyone marked do not contact, are left out, and the count says so. The post office check on each address runs later, when the card is made, and anything it holds comes back to you as a list to fix (see below).
Step 2: Design
What you are mailing.
Three doors lead to a design. They all end at the same print check:
- Use my own design. Upload the front and the back as JPG or PNG files. We ask which size it is (4x6, 6x9 or 6x11) and show the real price for it.
- Make one here. Opens the Design Studio. Pick a style, shuffle layouts, colors and fonts until it looks right, apply it, and you come straight back to the send.
- Use a saved design. Designs you have already made, with approved ones first.
The print check
Whatever door you used, you see the card the way it will print, with a warning for anything too close to the edge or over the address area. Read the headline at actual size, check the phone number and the QR code, and look at anything near the edge: the printer can trim about an eighth of an inch.
When it looks right, tick Looks right and press Continue. This is the last point at which a mistake is free: a mistake that matches the proof you approve is not refundable. A design you have already approved goes straight through on later sends. If you edit it afterwards, it needs a new check.
Step 3: When
Three ways to send, and an optional follow-up.
- Send now. Every card goes to print right away. This is the default.
- Spread it out. Cards go out a few a day over 1, 2 or 4 weeks, and each choice says the real pace, for example "About 3 a day, done in about 3 weeks". Responses arrive in proportion to cards delivered, so spreading a big list out keeps the phone calls from landing in one lump.
- Send on a date. All the cards go to print on the day you pick (below).
Under the three choices is Add follow-up cards, a Pro feature. Turn it on to mail the people who have not answered again, with the number of cards and the wait between them your choice. On Free, a send is one card per person. Pro can also add phone follow-up calls from the same screen; see Call Queue and Scripts.
Sending on a date
If the cards should not go out today, choose Send on a date and pick the day. The earliest is tomorrow, and you see the answer as you pick: the day the cards go to print and the day most should arrive.
- Mail only goes out on weekdays. If you pick a Saturday or Sunday, the day moves to the next weekday and the screen tells you.
- The date can be up to 180 days ahead.
- In Advanced view you can instead pick Arrive by, the day you want most cards in mailboxes, and we work back to the day they go to print. This suits a promo with a deadline or an event. Arrival dates are targets, not promises; the Postal Service sets the final pace.
- Public holidays are not accounted for.
You pay in Pay, as for any send: your card is charged to fill the wallet now, and each card is paid from the wallet when it prints on the day. On that morning we run the same checks as a send today. If something fails, for example a design that lost its approval, the send does not go out, the mailing page shows the reason, and the account owner gets an email. Fix it and schedule again.
Step 4: Pay
Ready to mail.
The last step shows your design, your list, the When choice, and the price: the number of cards times the price of one, with printing, postage and tracking included. The price of a card depends on its size and your plan. You can rename the mailing here.
- If your wallet covers the cards, the button reads Send N postcards now and nothing is charged.
- If it does not, the button reads Pay $X and send now. Your saved card is charged, or you add one on the spot. Whatever is not used stays in your wallet.
- With no return address on file, a short form sits above the button. Fill it in, and it is saved for next time.
- Turn on auto-reload is an optional box. It adds the amount you pick to the wallet, on the card you have on file, when the wallet runs low while cards are going out, so a send does not pause halfway.
A declined card, or a bank check, keeps you on this step with the reason in plain words. If a payment went through but the cards did not go out, you are told so, and trying again never charges you twice.
After you send
The Sent screen says how many cards are going to print and shows the cancel window: each card is held for four hours before it prints, and you can cancel any card in that time for a full refund. Press See this mailing to open its page.
The mailing page shows delivered, in transit and printing counts, the cancel window while it is open, and QR visits as people scan. Turn on Advanced view for the Timeline tab, which shows a row for each person, with a marker on the day each card went out and the day it arrived. First-Class delivery typically takes about a week from the day a card prints, so the first scans show up about a week after you send, not the next morning.
If you added follow-up cards, each one goes out after its wait, to the people who have not answered. Anyone whose next card has no approved design yet waits rather than being skipped, and the card goes out by itself once the design is approved.
Addresses the post office check holds
When an address fails the check, the card is held, not mailed, and you are not charged. The mailing page lists the cards held and the ones that came back, with the post office's closest match when there is one. Use the match, fix the address by hand, or skip the person. A fixed address is mailed again. A card that already went out and came back was charged; fixing the address sends a new card.
Sending again
Once a one-card mailing has gone out, Send again on its row or its page starts a new send to the same people with the same design, and opens at Pay when the design is already approved. It is offered for mailings with one card and no calls.
Snags that come up
- "No one on this list can be mailed." Every person on the list is missing part of the address or is marked do not contact. Fix the addresses in Contacts, or choose another list.
- The print check is slow. The first check on a new design takes a minute or two. You can leave the page and it keeps going.
- Looks right is greyed out. The check is still running. Wait for the preview to finish.
- Only one card is offered. Follow-up cards and calls are Pro. On Free, a send is one card per person, and the upgrade window opens when you switch follow-ups on.
- A scheduled send did not go out. Something failed the checks that morning, for example a design that lost its approval. The mailing page shows the reason and the account owner gets an email. Fix the problem and pick a new date.
- The Sent screen says "Some cards are waiting." The wallet ran out partway through. Add funds, and press Resume on the mailing if it is paused. Auto-reload prevents this.
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