2 sentences for 有效期 (yǒu​xiào​qī — validity period)

1. 这份护照的有效期是十年。

   zhè fèn hù​zhào de yǒu​xiào​qī shì shí nián.

   This passport is valid for ten years.

   Source: Dong Chinese Dictionary

2. 护照持有人必须在有效期内入境。

   hù​zhào chí​yǒu​rén bì​xū zài yǒu​xiào​qī nèi rù​jìng.

   The passport holder must enter the country within its validity period.

   Source: Dong Chinese Dictionary