How ASM calculates a shipping rate

Every time a shopper reaches checkout, your store asks ASM: "What shipping options does this cart have to this address, and what do they cost?" ASM answers in a few seconds. This article explains what happens in between, so the rest of the help center makes sense.

Beginner · How it works

The journey of one quote

The eight steps of a quote: your store asks, ASM checks it's on, finds your products, rules pick methods, packs the cart, prices each box, adjusts the price, answers checkout

  1. Your store asks. The shopper enters an address at checkout (or a ZIP code in a Turbify cart). Your platform sends ASM the cart's products, quantities and the address.
  2. ASM checks it's on. If Enable Advanced Shipping Manager in your store is off, ASM's rates don't show. See Turn ASM on (or off) at checkout.
  3. ASM looks up your products. It finds each product by its SKU or product ID, with the shipping settings you've given it in ASM: weight, size, where it ships from, any restrictions. A product ASM can't find can't be rated. See How products get into ASM.
  4. Your shipping rules decide which methods apply. Each rule is one method shoppers can pick, such as "UPS Ground" or "Free Shipping". A rule only applies when its conditions pass: the destination, the order value, the weight, and so on. See How shipping rules work.
  5. ASM packs the cart into packages. It groups items into boxes using their weights and sizes, and splits them by origin when products ship from different places.
  6. ASM prices each package. Depending on the rule, the price comes from a carrier's live rates (UPS, FedEx, USPS, freight carriers and others), or from a flat or table rate you set. For live rates, the address type matters: carriers often charge more for residential delivery. See Residential vs. commercial addresses.
  7. ASM adjusts the price. Your markups, handling fees and free-shipping rules are applied. See Add a handling fee.
  8. ASM answers your checkout. The methods that passed, with their final prices, go back to your store. Shoppers pick one.

Shipping Estimator results with First Class Mail USA Only expanded: package 1, 0.750 LBS, shipping $12.10, markup $0.00, rate $12.10

Why this matters when something looks wrong

Each step is a place where a method can drop out or a price can change:

  • A method is missing usually means a rule's condition didn't pass (step 4), or a carrier returned an error or didn't answer in time (step 6).
  • A price is too high often means more packages than you expected (step 5), a wrong product weight (step 3), or a markup (step 7).
  • No methods at all often means ASM is off (step 2), a product isn't in ASM (step 3), or no rule matched (step 4).

The Shipping Estimator shows you the result of every step for any cart: which methods came back, the packages behind each price, the markup, and any carrier errors. See Test your rates with the Shipping Estimator and Read Shipping Estimator results.

Checkout has a time limit

Your platform waits only a few seconds for ASM's answer. A carrier that's slow to respond can miss that window, and its methods are left out of that checkout. This is the main reason a method can show in the Shipping Estimator but not at checkout. See Why the estimator and checkout can differ.

Words you'll see

  • Method — one shipping option shoppers can pick, such as "UPS Ground".
  • Rule — the settings behind a method: when it shows and how it's priced.
  • Carrier — the company that moves the package: UPS, FedEx, USPS, a freight carrier and so on.
  • Origin — the address a package ships from.

More terms: Glossary.

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