記入 and 入力: filling in a form and entering data
Compare writing on a form with entering values on a screen, distinguishing entry from saving or sending the information.
Writing required information in the designated place
記入, read きにゅう, means filling in required information on a form or in a designated space. 用紙の上の欄に氏名を記入してください。 asks for a full name in the upper field of the form.
記入例を見て、必要な項目を書きました。 says that the required fields were filled in after consulting an example. 記入例 shows how to complete the form, not the applicant's actual information.
Entering information into a device or system
入力, read にゅうりょく, means entering information into a device or system. 画面に電話番号を入力しました。 says that a phone number was entered on the screen.
入力した内容を確認してから送信してください。 asks someone to check the entered information before sending it. Preserve the sequence of entry, checking, and transmission.
Typical media and the scope of completion
記入 is common with paper forms and 入力 with screens, but 記入する can also be used for online forms. Do not limit 記入 to handwriting alone.
入力は終わりましたが、まだ保存していません。 says that entry is finished but the information has not yet been saved. Entry alone does not establish completed saving or transmission.
What comes before sending in 入力した内容を確認してから送信してください。?
Show the answer and why
Checking the entered information. 確認してから places checking before transmission.