Most of my cross border travel has been by plane, and I am a US Citizen. For business and pleasure (hunting and firearms) I often filled out the CBP 4457 so that personal items can be brought back to the USA without paying duty. For firearms, it is a necessity, no need to explain import and export of firearms. Don't go there unless you want to make a business out of it. Also, for expensive items that can be bought abroad. You know, watches, purses, electronics, stuff like that.
Crossing in a camper is new to me. I am not worried about the camper, I have the normal paperwork for that, but are there items that might fall under the rules? Customs doesn't seem to care about smart phones, computers, etc. The TV's are so cheap who cares, but am I missing something? Anybody get dinged for duty on something they bought in the US, but just did not have the paperwork covered?
I am gun shy (my pun) because on my first trip out of the US, and into Canada I found out the hard way. Canada required no paperwork to get the gun into Canada (40 years ago folks), but many thanks to the Canadian customs man that asked me if I had the paperwork to get the gun back home. He told me as of right now the gun was forever doomed to stay in Canada. Then he laughed told me to turn around go back to the US side, and who to see to get it all set right. They all got a good chuckle at the look on my face, but they fixed it for me. Lesson learned.
So can anyone teach me an easy lesson?