What must passengers declare at customs upon entering another country?

The requirement for passengers to declare any items exceeding allowance limits or restricted/banned items at customs is grounded in international regulations designed to ensure safety and compliance with a country's import laws. Each country has specific rules regarding what can be brought into its borders, including limits on quantities and types of goods—such as alcohol, tobacco, food products, or items that are otherwise prohibited.

When passengers declare items that exceed these limits or include items that are restricted or banned, they are helping customs officials to monitor and control what enters the country. This process is important for protecting public health, safety, and economic interests. Additionally, failing to declare such items can lead to fines, confiscation of goods, or other penalties, reinforcing the importance of compliance.

The other options do not align with customs declaration requirements. Declaring all items purchased abroad is too broad and not always required; passengers may only need to declare items that exceed legal limits. Reconciling travel expenses is part of personal finance management and not relevant to customs. Stating reasons for traveling might be necessary for visa purposes but does not pertain directly to customs declarations.