納入 and 納品: shared goods delivery and 納入 for tuition payment
Compare 納入 of equipment or tuition with 納品 of goods. Read the object as goods or money, keeping a deadline check separate from completed payment.
Supply equipment with 納入
納入, read のうにゅう, means delivery in this equipment context. 会社は注文された機器を期限内に納入した。 says that the company delivered the ordered equipment within the deadline.
Ordered equipment is the supplied object and 期限内 the action's time condition. In goods-supply scenes, 納入 can overlap with 納品.
Deliver completed goods with 納品
納品, read のうひん, means delivery of goods. 完成した部品を予定どおり納品した。 says that the completed parts were delivered on schedule.
The parts' completion and delivery on schedule are stated. Preserve the goods-supply overlap rather than making the terms mutually exclusive in every delivery scene.
Tuition payment and a check before delivery
学費の納入期限を案内書で確かめた。 says that someone checked the tuition payment deadline in the guide. The object of 納入 is money, while checking the deadline is the completed action.
納品の前に数量と品質を確認する。 says that quantity and quality are checked before delivery. Preserve the order without reporting already completed checking or delivery, or inventing a specific deadline system.
Is the object of 納入 in 学費の納入期限 goods such as parts?
Show the answer and why
It is tuition money in this context. Distinguish equipment delivery from tuition payment by the object, and do not turn checking the deadline into already paying the tuition.