This guide shows how to configure USPS in Shipi. You connect your own USPS business account through the USPS APIs, so Shipi can show USPS rates at checkout and buy USPS labels that are paid from your USPS Enterprise Payment System (EPS) account.
| Item | Details |
|---|---|
| What you need | Consumer Key and Consumer Secret, CRID, Mailer ID (MID) and EPS account number |
| Where to get them | The USPS Developer Portal (API keys) and the USPS Business Customer Gateway (CRID, MID, EPS) |
| Services | 12 domestic and 4 international USPS services |
| Live rates | Yes, commercial or retail prices |
| Label formats | PDF, TIFF, SVG, JPG, ZPL 203 dpi, ZPL 300 dpi; 4×6 or 6×4 |
| Options | Insurance, signature, collect on delivery (COD), hold for pickup, customs content type |
| Setup steps in Shipi | Carrier Account → Package → Shipping Services → Rates → Shipping Label |
Most common mistake: the CRID, MID and EPS account number don’t belong to the same USPS business account as the API keys. USPS then refuses to pay for the label: USPS Payment Authorization failed. Check your CRID, MID, and Account Number.
In this guide: What you need · Add USPS · Account information · Ship-from address · Packing · Services · Rates · Label settings · First label · Troubleshooting · FAQ
What you need to configure USPS
- A USPS business account in the USPS Business Customer Gateway. It gives you your CRID (Customer Registration ID) and Mailer ID (MID).
- An Enterprise Payment System (EPS) account, set up in the Business Customer Gateway. USPS takes postage for Shipi labels from it.
- An app on the USPS Developer Portal linked to that business account. It gives you the Consumer Key and Consumer Secret.
Step 1: Add USPS in Shipi
- Sign in to Shipi and click Carriers in the left menu. The Shipping Accounts page opens.
- Click Add Shipping Account. If you haven’t added any account yet, the page shows the carrier list straight away.
- In the Add New Shipping Account window, search for USPS and click it.
- The setup form opens. Its steps are listed in the Setup Steps panel on the left: Carrier Account → Package → Shipping Services → Rates → Shipping Label. Click Next at the bottom of each step, and Save Settings on the last one.
The left panel also has a Book a call button. The Shipi team can set up USPS with you for free.
Step 2: USPS account information
| Field | What to enter |
|---|---|
| Shipping Account Name * | Any name to recognise the account, for example USPS – Main Warehouse |
| Execution Mode * | Live Mode (default) buys real labels. Test Mode uses USPS’s testing environment; use it with test credentials from USPS. |
| Consumer Key (Client ID) * | From your app on the USPS Developer Portal |
| Consumer Secret (Client Secret) * | From the same app |
| Customer Registration ID (CRID) * | From the Business Customer Gateway |
| Mailer ID (MID) * | From the Business Customer Gateway |
| Manifest MID | The Mailer ID used for manifests. If you don’t have a separate one, enter your Mailer ID again. |
| EPS Account Number * | Your Enterprise Payment System account number. USPS charges postage to it. |
Step 3: Ship-from address
The Shipping From Address section is under the account fields on the first step. USPS uses it as the sender on every label, so enter the address your parcels leave from.
If you already have saved addresses
- Shipper addresses saved in your Address Book appear as cards. Click a card to use it for this account; it gets a green Default badge.
- Click Edit on a card to change it, or + Add New Address to add another.
If you don’t have a saved address yet
| Field | What to enter |
|---|---|
| Shipper Name * | The contact person, printed on the label |
| Company Name * | Your business name |
| Mobile / Contact Number * | A phone number the carrier can call about the shipment |
| Email Address * | Your shipping contact email |
| Address Line 1 * | Street and number |
| Address Line 2 | Unit, floor or building (optional) |
| Country * | The country you ship from |
| State * | Choose from the list for that country |
| City * | Your city |
| Postal/Zip Code * | Your postal code |
| Tax ID / GSTIN | Your VAT, EORI or other tax number, if customs documents need it (optional) |
| House Number | Only if your address has the house number separate from the street (optional) |
The + Add New Address window has the same fields, plus + Add Custom Field to store any extra reference with the address.
Step 4: Packing
The Package Settings step tells Shipi how to turn an order’s items into parcels for USPS. Shipi works from your product weights and dimensions, so make sure your products have them.
| Option | How it packs | Use it when |
|---|---|---|
| Pack Items Individually | Every item goes in its own parcel. | Each product ships in its own box. |
| All in one box | All items go in one parcel, whatever their size. | Your orders always fit in one box. |
| Weight Based Packing (Heavy Items First) (default) | Fills a parcel, heaviest items first, up to Max Weight (kg) (25 by default), then starts a new parcel. | You don’t use fixed box sizes. |
| Box or tube or envelope or packet packing | Fits the items into the boxes you define, using their dimensions. | You ship in a few standard box sizes. |
Adding your boxes
With the box option selected, click + Add Box and fill in:
| Field | What to enter |
|---|---|
| Name * | Any name, for example Small Box or Large Mailer |
| Type * | Box (rigid box), Tube (rolled items such as posters), Envelope (documents and thin, flat items) or Packet (soft mailer bag for items that don’t need a box, such as clothes) |
| Weight of Box (kg) * | What the empty packaging weighs |
| Max Weight (kg) * | The most the box can hold, items and packaging together |
| Width (cm) * | Left to right |
| Height (cm) * | Bottom to top |
| Depth (cm) * | Front to back |
Each box appears as a card with Edit and Remove buttons.
Packing settings greyed out? Your store uses one central packing configuration for all its shipping accounts. Click Edit Configuration, then Yes, Edit Settings. Your changes then apply to every shipping account in the store.
More detail and examples: how shipping package configuration works in Shipi.
Step 5: Shipping services
This step lists the USPS services Shipi supports. Only the services you tick are used: in rates at checkout and in the service list when you create a label.
- Type in Search services… to find a service, or use the All, Domestic and International tabs.
- Tick the box on a service card to switch it on. Each card shows the service code in brackets, for example
[CODE]. - Click the gear button on a ticked service to open Configure:
:
| Setting | What it does |
|---|---|
| Display Name | Your own name for the service, used instead of USPS’s name in the service list when you create a label and in the rates your customers see at checkout. Leave empty to keep the standard name. |
| Price Adjustment % | Saved with the service, but it isn’t added to USPS rates at the moment: rates show USPS’s own price. |
| Type | Services |
|---|---|
| Domestic | USPS Ground Advantage, Priority Mail, Priority Mail Express, Parcel Select Ground, Parcel Select Lightweight, Parcel Select Destination Entry, USPS Connect Local, USPS Connect Regional, First-Class Package Service, Media Mail, Library Mail, Bound Printed Matter |
| International | Priority Mail International, Priority Mail Express International, First-Class Package International Service, Global Express Guaranteed |
Step 6: Rate settings
| Setting | Options | What it does |
|---|---|---|
| Enable Realtime Shipping Rates * | Yes / No | Yes shows USPS prices at checkout. No hides them at checkout; you can still get rates when you create a label. |
| Price Type * | Commercial / Retail | Commercial is the discounted business price most accounts get. Retail is the Post Office counter price. |
| Default Processing Category * | Machinable / Non-Machinable | Machinable parcels go through USPS sorting machines (regular boxes). Choose Non-Machinable for odd shapes, rolls or very light or heavy items. It changes the price. |
| Include Insurance in Rates * | No / Yes | Yes adds USPS insurance to the rates you show. |
| Signature Requirement | No Signature Required / Signature Confirmation / Adult Signature Required / Adult Signature Restricted Delivery | Adds the signature service to rates and labels. You can change it per label. |
Step 7: Shipping label settings
| Setting | What it does |
|---|---|
| Shipping Label Generation Time | Create Label Manually: you create each label from Shipments. Create Label immediately once order placed: Shipi creates the label as soon as an order with one of this account’s shipping options reaches Shipi. |
| Email address to sent Shipping documents * | Where Shipi emails the label (and invoice, if there is one) each time a label is created. Separate several addresses with commas. If an automatic label fails, Shipi emails the error instead. Leave empty if you don’t want emails. |
| Label Image Format * | PDF, TIFF, SVG, JPG, ZPL 203 DPI or ZPL 300 DPI. Choose ZPL for a thermal label printer. |
| Label Size * | 4×6 Label or 6×4 Label |
| Planed Shipment Days from Label Generation * | Same Day, +1, +2 or +3 days. Sets the default mailing date on the label; you can change it per label. |
| Shipment Content * | A description of the goods, for example T-shirts. It also goes on customs forms for international labels. |
| Non-Delivery Option (International) | What USPS does with an international parcel it can’t deliver: Return to Sender, Redirect or Abandon. |
| Hold For Manifest | Leave it on No. Shipi creates each USPS label straight away; this setting has no effect. |
Every Shipi USPS label includes USPS Tracking.
Before you switch on automatic labels: create one test label and check the service and price are right. Automatic and bulk shipments use your default service when the order has no service chosen at checkout.
After you save
Click Save Settings. The account appears on the Shipping Accounts page with its name, shipper, address and the USPS logo.
| Control | What it does |
|---|---|
| Status switch | On: the account is used for live rates. Off: Shipi leaves it out of rates. |
| Edit | Opens the setup form to change any setting |
| Delete (bin icon) | Removes the account |
| Custom Shipping Rule | Set a free-shipping threshold, choose one default domestic and one default international carrier account (with a service), and send chosen countries to a specific account |
Create your first USPS label
- Click Shipments in the left menu.
- Click Create Label next to an order, or Create Shipment to ship something that isn’t an order.
- Check the shipper and receiver details and the products, then choose your USPS account and a service.
- Click Get Rates to see the price of the selected service.
- Set the shipment options below if you need them, then click Create Shipment.
- Shipi shows the tracking number and the label to print. If you entered an email address in the settings, the label is emailed too.
USPS options on the label screen:
| Option | What it does |
|---|---|
| Shipping Service / Get Rates | The USPS service for this label and its price |
| Insurance | Adds USPS insurance based on the value of the goods |
| Signature Confirmation | Same choices as the account setting, for this label only |
| When you ship? | The mailing date: today or one of the next 6 days |
| Collect on Delivery (COD) | USPS collects payment from the receiver |
| Hold For Pickup | USPS holds the parcel at the Post Office for the receiver to collect |
| Customs Content Type (International) | Merchandise, Gift, Documents, Sample, Return, Humanitarian or Other |
| Shipment Content | The goods description for this label |
Troubleshooting
| Message or problem | What to do |
|---|---|
| Error while packing: Check whether the products having weights / dimensions. | One or more products has no weight or dimensions. Add them to the product (or the shipment) and try again. |
| USPS Authentication failed. Check your credentials. | Check the Consumer Key and Secret, and that Test/Live Mode matches them. |
| USPS Payment Authorization failed. Check your CRID, MID, and Account Number. | The CRID, MID, Manifest MID or EPS account number is wrong, or they belong to a different USPS account than the API keys. |
| client_id is required. (or another field name) | That account field is empty. Open the account with Edit and fill it in. |
| No tracking number returned from USPS. Response: … | USPS refused the label; the text after Response explains why (for example an address or weight problem). |
| No USPS rates at checkout | Set Enable Realtime Shipping Rates to Yes, switch on the account’s status, and tick the services you want. |
Frequently asked questions
A USPS business account with a CRID and Mailer ID, an Enterprise Payment System (EPS) account for postage, and a Consumer Key and Secret from an app on the USPS Developer Portal.
USPS charges the postage to the EPS account number you enter in the account settings.
Choose Commercial if your account has commercial pricing, which most business accounts do. Retail shows Post Office counter prices.
Machinable parcels are regular boxes that go through USPS sorting machines. Non-Machinable is for odd shapes, rolls and some very light or heavy items and costs more. Shipi uses the default you choose for rates and labels.
Yes. Choose ZPL 203 DPI or ZPL 300 DPI as the Label Image Format, and 4×6 as the label size.
Yes. Set Enable Realtime Shipping Rates to No. You can still get USPS rates and create labels from the Shipments page.
Related guides
- How to configure shipping accounts in Shipi
- How shipping package configuration works in Shipi
- How to configure UPS in Shipi
- How to configure FedEx in Shipi
Last updated: September 24, 2026