I buy things from foreign websites and haveEcommerce & Shopping

Task prompt

I buy things from foreign websites and have them sent to South Korea, and I have been caught out by the same order clearing smoothly once and being held for a formal declaration the next time. I want to understand why. Work out from the customs service's own English pages how a parcel is treated differently depending on whether it arrives by courier, through the post, or in my own luggage, because I am fairly sure the value limits are not the same for all three and I have been assuming one number covers everything. Also tell me what identifier I personally have to provide, since I am told a passport number is not accepted. Where a rule depends on the country the goods were bought in, say so. Where the pages do not answer something, say plainly that they do not rather than filling the gap from memory. Do not create any account, register anything, or enter personal details anywhere. Rank the three channels for a single order and tell me which one to use.