---
title: "Connect an existing carrier account using OAuth 2.0"
method: GET
path: "/carrier_accounts/{CarrierAccountObjectId}/signin/initiate"
tags: ["Carrier Accounts"]
---

# Connect an existing carrier account using OAuth 2.0

`GET /carrier_accounts/{CarrierAccountObjectId}/signin/initiate`

## Request

- Base URL: `https://api.goshippo.com`
- URL: `https://api.goshippo.com/carrier_accounts/{CarrierAccountObjectId}/signin/initiate`
- Auth: API key in header `Authorization`

Used by client applications to setup or reconnect an existing carrier account with carriers that support OAuth 2.0

## Path parameters

- `CarrierAccountObjectId` string, required

## Query parameters

- `redirect_uri` string, uri, required
- `state` string

## Headers

- `SHIPPO-API-VERSION` string
- `SHIPPO-ACCOUNT-ID` string

## Other responses

- `302`: Redirects the browser to the carrier login page, with the needed parameters
- `400`: Invalid parameters provided by the user
- `401`: Invalid ShippoToken or unsupported carrier account provided by the user
- `404`: Invalid carrier account provided by the user

## Changes

- **2026-10-28** `0eab5a94b0c3`: 1 info
  - added the new optional `header` request parameter `SHIPPO-ACCOUNT-ID`
- **2026-07-12** `7e1ec201b515`: 1 breaking
  - for the `header` request parameter `SHIPPO-API-VERSION`, default value `2018-02-08` was added

[Operation history](https://skmtc.dev/goshippo/apis/shippo-external-api/changes/carrier_accounts/:CarrierAccountObjectId/signin/initiate/get.md)

---

[API](https://skmtc.dev/goshippo/apis/shippo-external-api.md) - [All operations](https://skmtc.dev/goshippo/apis/shippo-external-api/llms.txt) - [OpenAPI document](https://skmtc.dev/goshippo/apis/shippo-external-api/revisions/0eab5a94b0c3?raw)