Customs declaration is required, and cultural relics (ancient coins) are explicitly prohibited from leaving the country. If you leave the country, you must do cultural relics identification.

As long as it is identified as a cultural relic, even if it is a general cultural relic, it is smuggling if the name is not truthfully filled in. If one of them is a third-class cultural relic, it constitutes a smuggling crime.

Some things are not worth mentioning at home, but they just can't leave the country.