Convert numbers to kanji numerals and daiji (formal kanji) for invoices and contracts
12,345
一万二千三百四十五
e.g. 一万二千三百四十五 — for general documents
壱萬弐千参百四拾五
e.g. 壱萬弐千参百四拾五 — tamper-proof forms of 一/二/三/十/万
金壱萬弐千参百四拾五円也
e.g. 金壱萬円也 — for receipts, gift envelopes and contracts
一二三四五
e.g. 一二三四五 — for vertical addresses and phone numbers
Daiji is the formal way of writing kanji numerals (一→壱, 二→弐, etc.). Because simple numerals can be altered (e.g. 一 into 二), daiji is used on receipts, contracts and registry documents to prevent tampering with amounts.
They are used wherever you want to prevent tampering with amounts, such as on receipts, contracts, official registration documents, and gift money envelopes. Because '一' (one) could be altered into '二' (two) or '三' (three) by adding strokes, the formal forms '壱,' '弐,' and '参' are used instead.
'也' (nari) is placed at the end of an amount to indicate 'this is the end,' preventing additional figures from being appended. It is a traditional notation used on gift envelopes and receipts.
