Problem
When Linnworks updates the Shopify order to mark it as shipped, the incorrect carrier can be added to the order instead of the carrier that is defined in the Vendor field of the Linnworks Postal Service Method.
Cause
Linnworks use Shopify automated tracking-number system and where possible will attempt to match the Carrier name to those predefined by Shopify, however in the event of no match is found, Shopify will use internal logic to assign another vendor.
Solution
List of all the shipping vendors that Shopify supports:
- 4PX
- APC
- Amazon Logistics UK
- Amazon Logistics US
- Australia Post
- Bluedart
- Canada Post
- China Post
- Chukou1
- Correios
- DHL Express
- DHL eCommerce
- DHL eCommerce Asia
- DPD
- DPD Local
- DPD UK
- Delhivery
- Eagle
- FSC
- FedEx
- FedEx UK
- GLS
- Globegistics
- Japan Post (EN)
- Japan Post (JA)
- La Poste
- New Zealand Post
- Newgistics
- PostNL
- PostNord
- Purolator
- Royal Mail
- SF Express
- Sagawa (EN)
- Sagawa (JA)
- Singapore Post
- TNT
- UPS
- USPS
- Whistle
- Yamato (EN)
- Yamato (JA)
- YunExpress
To check if there is the appropriate vendor specified in Linnworks:
1. Go to Linnworks.net > Shipping > Postal Services.
2. Check column Vendor 

3. Edit vendor name to one of the above if required.