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だったら
tekikakuseikyū shotō hozonhōshikidattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 適格請求書等保存方式

1. If/when it were a qualified invoice preservation method.; If/when it was a qualified invoice preservation method.

Tara Conditional
Law