適格てきかく請求せいきゅうしょとう保存ほぞん方式ほうしきでした
tekikakuseikyū shotō hozonhōshikideshita

Noun
Desu Copula

The polite past form of 適格請求書等保存方式

1. Was a qualified invoice preservation method.

Past/Perfective
Polite
Law