(I am in New Zealand, but am interested in answers following British style law..
When entering into New Zealand (as with most countries), passengers are required to fill out an arrival card. At the bottom of this arrival card it states "I declare the information I have given is true, correct, and complete". The document also states "This arrival card is a legal document - false declarations can lead to penalties...".
A person is cited for "being required to make a declaration in relation to goods specified in that declaration, erroneously declared..." - where the only document in question was an arrival card. There was also a brief discussion with an MPI agent.
The act allegedly contravened is the Biosecurity Act 1993 - however this act does not define the word declaration, or use it this context.
There is another act - the Oaths and Declarations Act 1957, which does, in section 8-10 define "Manner of making declarations". If the arrival card meets neither the oath/affirmation requirementnor form or wording of the Oaths and Declarations Act - which seems to be the case here, legally speaking, [can and how/by what interpretation] be charged for making a false declaration such that it will hold up in court?
Relatedly, and maybe not clearly implied in the above question - (1) Can a declaration be verbal? (2) Relating to (minor) criminal charges ala parking tickets, does a declaration have to be in the form/is it covered by the Oaths and Declarations Act?