I have tried printing a Parcelforce shipping label and am seeing an error returned:

PersonalParcel is not enabled for department


This error is returned if the Age Verification option found in > Shipping > Integrations > Parcelforce > Services > Edit is not enabled for your account, but has been enabled in Linnworks. You would need to contact Parcelforce and ask them to enable it for your Contract Number to resolve the error.

Additionally, a specific Department ID may need to be passed, so you will need to double-check whether you have the correct Department ID entered in > Shipping > Integrations > Parcelforce > Config. If it is set incorrectly, or simply set to 0, contact support to get it updated to the correct value.