You may have noticed when booking shipments via APC that your 'delivery type' is auto-filled with an option that fulfils certain conditions. There are 3 possible options, Sender, Recipient and Third Party.
The criteria of each delivery type is listed below:
Sender
Collection (From): Operational Address with Company Name therefore the Pick-Up Address (your account)
Delivery (To): Any Delivery Address
Recipient
Collection (From): Any Pick-Up Address but NOT Operational Address with Company Name
Delivery (To): Operational Address with Company Name (your account)
Third Party
Collection (From): Any Pick-Up Address but NOT Operational Address with Company Name (your account)
Delivery (To): Any Delivery Address
Note: third party does not allow you to manifest orders within New Horizon. Also, the cut-off time is 12:00 and anything after gets shifted to next day
It's important that the address you want to be your collection address must be set within APC and Shiptheory otherwise this could cause an issue and result in the wrong delivery type.
If you have any others issues or questions please don't hesitate to contact support.