Transit times by route, from a logged dataset — the long version

Customs outcomes are not predictable at the level of an individual parcel. What is predictable is that consistent, accurate declarations correlate with fewer interventions, and that the same route behaves differently in different months.

Picking up post #13: that is the part I would want checked first.

For anyone arriving from a search: the marked solution above is the direct answer, and the replies underneath it add the caveats that make it safe to use.

Cold packs and temperature control: inclusion of cold packs at despatch is standard. Whether they maintain temperature through transit depends on journey duration and ambient temperature. Long journeys through warm climates put product at risk.

Tracking stops updating: tracking last updated days ago usually means the package is in transit and will not update until it reaches the next scanning point. No update for weeks means it might be stuck.

I read post #17 twice before replying, because I had assumed the opposite.

Reshipment after seizure: if a parcel is seized, some suppliers will reship; others will not. That is a supplier choice and should be understood before ordering in a jurisdiction with higher seizure risk.

Packaging integrity on arrival: if a parcel arrives with compromised packaging, that is evidence of a handling problem in transit. The contents may or may not be compromised but you have reason to be cautious.

Customs holds: if a parcel is held at customs and you can contact customs directly, declaring your personal use and providing documentation (order, labelling) can help. Most customs officials are reasonable when they know what they are dealing with.

Import restrictions by jurisdiction: what is legal to import for personal use varies enormously by country. Some jurisdictions are quite permissive; others are not. Checking your own country's rules before ordering is prudent.

Worth separating two things that post #20 runs together.

Documentation after arrival: photograph the parcel and its contents on arrival. If something later turns out wrong (damage, loss, wrong item) you have evidence of the condition it arrived in.

I disagree with the reply above, and I think the disagreement is substantive rather than terminological.

The distinction being drawn does not survive when you look at the published data for this specific question. I would be glad to be shown wrong on this, because the version I am arguing against is more convenient.

At what point is a parcel genuinely a problem: if it was despatched weeks ago and there has been no update for days at customs, it might be held or lost. Days of delay at customs without update is ordinary; weeks without movement warrants inquiry.

post #26 answers the question as asked. The question underneath it is different.

Declaring contents accurately: declaring accurately reduces intervention risk. A declaration of "peptide research chemical, 5 grams" is better than "vitamin" or "other" because custom officials can verify a declared chemical is actually what was declared.

On post #24 — agreed on the reasoning, with one qualification.

Tracking stops updating: tracking last updated days ago usually means the package is in transit and will not update until it reaches the next scanning point. No update for weeks means it might be stuck.

Declaring contents accurately: declaring accurately reduces intervention risk. A declaration of "peptide research chemical, 5 grams" is better than "vitamin" or "other" because custom officials can verify a declared chemical is actually what was declared.

I read post #28 twice before replying, because I had assumed the opposite.

Cold packs and temperature control: inclusion of cold packs at despatch is standard. Whether they maintain temperature through transit depends on journey duration and ambient temperature. Long journeys through warm climates put product at risk.