Langley HWDC/customs process for outbound international parcels

[Smat_NM]

Hi,
I have tried searching but as most enquiries here are rather specific, didn't quite find the answers I was looking for.

I've recently sent a parcel to the US and in the interest of keeping the receiver informed as best I can, I'm curious as to where the customs department falls in outbound international parcels processed at Langley HWDC.

I have the updated tracking information (as of 02:50 0n 27/10/2022) of:

In Transit. "Item leaving the UK. Langley HWDC" with section marked Handed To: Delivery partner. "Your item is now leaving the UK. More information will be available when it arrives in the destination country."

On checking the USPS website tracking, I have the following information:
"Pre-shipment: Origin post is preparing shipment" (latest),
Processed through facility - Langley HWDC

As I've previously experienced delays from customs before (though only on inbound parcels), could this still be subject to delays caused by the customs process on the UK side or does the above information indicate that any customs processes have been completed (again only enquiring about the UK side).

Thanks for any help

[Snaggletooth]

It is the receiving country that perform the actual customs checks, so the USA in this case.

Royal Mail seem to carry out some checks on outbound mail. However, your tracking indicates that this item has gone past this stage and is now with US customs.

[Smat_NM]

Thank you very much for the info/clarification.