Posto is a Shopify app for inventory forecasting and purchase orders. It reads your sales, works out what to reorder and how much, and sends the order to your supplier. Here's what happens at each step, and what it saves you.
Posto forecasts demand from your store's own orders, currently around the last 60 days. It projects that forward, adds the lift you'd expect around Black Friday and the holidays, and updates as new orders come in.
Days a product was out of stock are left out. Otherwise a stockout makes demand look lower than it was, and your next order comes out too small.
Black Friday and the holiday rush are built in, so you're not ordering for November with October's numbers.
New products and slow sellers get a Limited history label, so you know when a number is a rough estimate.
For each product, Posto adds what you'll sell while the order is on its way, the days of stock you want once it lands, and a safety buffer. It subtracts what you already have, then rounds up to your supplier's minimums and case packs.
Example: a product that sells 5 a day, from a supplier who takes 14 days to deliver. The math comes to 153, and the case pack takes it to 156.
Every input is yours to change, for the whole store or a single product. Each recommendation also shows how long your stock will last next to how long a new order takes, and the sales at risk if you wait.
Read the reorder point guidePosto drafts one purchase order per supplier from its recommendations, with your saved costs filled in. You check the email and send it from Posto, with the PDF attached. Replies come back to your store's inbox.
If a delivery is past its expected date, Posto marks the order overdue, so it doesn't slip past you.
If a supplier's address bounces, you see it on the order, instead of waiting on a reply that was never coming.
Shopify's built-in purchase orders stop at a PDF you export and email yourself. Posto sends it for you.
Edit or cancel an order after it's sent, and email the update to your supplier straight from Posto.
Record what arrived, all of it or part of it, into the Shopify location you choose, and Posto updates your inventory. Add freight, duty, and fees, and Posto spreads them across the order for a true cost per unit.
Sold at $12, that mug earns a 58% margin, not the 67% the invoice suggests. That gap decides which products are worth reordering.
Receive what showed up today. The rest stays open on the order until it arrives.
Stock goes into whichever Shopify location you pick, and Posto confirms the units first.
Importing never changes your inventory. If an order was still open, receive it in Posto when it arrives, and only the new units are added.
Between orders, a few quieter features keep watch, so a slow week or a late shipment doesn't turn into an empty shelf.
Daily or weekly, most urgent first. If nothing is low, there's no email.
Import suppliers, costs, and past purchase orders by CSV, including Stocky exports, with a preview before anything saves. Export everything as one zip whenever you like.
Posto never reads customer names, emails, addresses, or payment details.
Set lead time, days of cover, and service level for the whole store or a single product.
Here's a single product, a 16 oz oat body wash, going through the whole cycle. Every number is worked out the way Posto works it out, so you can follow the math from the first sale to the cost on your shelf.
Posto looks at the last 60 days of orders and leaves out the days the body wash was sold out, so those days don't drag the average down.
The supplier takes 7 days to deliver, and you check stock once a week, so each order needs to cover about 14 days: 6 × 14 = 84. Add 21 units of safety stock, and the reorder point is 105. With 63 on hand and nothing on order, it's flagged Order now.
You want 30 days of stock once the delivery lands. That's 6 × (7 + 30) = 222, plus 21 safety stock, minus the 63 you have: 180. The supplier sells in cases of 12, and 180 is exactly 15 cases, so nothing needs rounding.
The body wash joins 96 cedar candles from the same supplier on purchase order PO-1002. You check it, and Posto emails it with the PDF attached. Replies come back to your inbox.
On October 19, all 180 body washes arrive, but only 90 of the 96 candles. You receive what came into your Austin warehouse, and Posto updates Shopify. The 6 missing candles stay open until you close the order short.
Freight was $118 and duty $42.50. Once you close the order short, they're spread across the 270 units that arrived, about 59¢ each, so every body wash really cost $4.39. That's the number to price and reorder against.
An illustrative example. Your own numbers will differ, and every input is yours to change.
You know your suppliers. Posto knows your sales. You give it a few facts once, and it does the arithmetic every day.
Each supplier's lead time, minimum order, and case pack. How many days of stock you want after a delivery. How careful to be, which sets your safety stock. Your product costs, imported or typed in. Change any of it for the whole store or a single product.
How fast each product really sells, with sold-out days left out and Black Friday and the holidays planned for. How long each supplier really takes, once 3 of their orders have arrived. Its reorder point and safety stock. How much to order, rounded to what the supplier sells. The sales at risk if you wait. And what each unit cost once it arrived.
Posto sits beside your store, not inside your checkout. Sales come in from Shopify, orders go out to your suppliers, and stock goes back into Shopify when it arrives.
Products, inventory levels, locations, and each order's date and quantities. Never customer names, emails, addresses, or payment details.
Inventory counts, when you record stock received on a purchase order, at the location you choose. If you turn it on in Settings, Posto also updates the cost per item of the products you receive.
Every order you create in Posto, from draft to received, sits alongside the history you import, so there's one place to look.
Your plan appears on your regular Shopify bill. Posto never sees your payment details.
Most inventory apps get more expensive as you grow and harder to understand as they add features. Posto was designed the other way around.
Every quantity comes with its breakdown. It's standard inventory math, not an AI black box.
Your bill doesn't grow because your revenue did.
Free included. Plans differ only by how many suppliers you order from.
Install it, bring your data, and send your first order. There's nothing to book.
Pay monthly through Shopify and cancel anytime on Shopify's plan page.
There's no demo to book and no onboarding call. Most of setup is telling Posto about your suppliers, and you can do it in one sitting.
Your 30-day free trial starts the first time you open Posto, with everything unlocked and no payment details.
Import them by CSV, from Stocky exports or any spreadsheet, or add them by hand. From Stocky's purchase order exports, Posto rebuilds your suppliers for you. Everything is previewed before it saves.
Add each supplier's lead time, minimum order, and case pack, and how many days of stock you want after a delivery. Once 3 orders from a supplier have arrived, Posto measures their real lead time for you.
See what to reorder and how much, with the math behind every number. Change anything that doesn't look right.
Check the draft and email it to your supplier from Posto, with the PDF attached.
From your store's own orders, currently around the last 60 days. Posto projects that forward with Black Friday and the holiday peak built in, and leaves out days a product was sold out so they don't drag the forecast down.
It covers your supplier's lead time plus the days of stock you want after delivery, adds safety stock, and subtracts what you have on hand and on order. Then it rounds up to the supplier's minimum and case pack. Every recommendation shows this breakdown.
Yes. Posto emails each purchase order from the app with a PDF attached, after you've reviewed it. Replies go to your store's inbox.
Yes. Edit or cancel the order in Posto, and email the update to your supplier straight from the app.
Add freight, duty, and fees to a purchase order, and Posto spreads them across its lines, by value or by units, to give a landed cost per unit. If you'd like, Posto can also update Shopify's cost per item with the landed cost when stock arrives, so your margin reports in Shopify come out right. It's off until you turn it on.
Yes. Receive whatever arrived, and the rest stays open on the order until it shows up.
Only when you record stock received on a purchase order, at the location you choose. Importing never changes inventory, and receiving an imported order only adds units that hadn't arrived yet.
Install Posto, bring your suppliers and costs over, and send your first purchase order. 30 days free, everything unlocked, no payment details.
Start your 30-day free trial