If you’re looking to rent an apartment in Japan, most of the time you probably won’t come across this term. Instead, 敷金 (deposit) and 礼金 (key money) would be more common but some apartments require you to pay the 内装代. So what is 内装代?
Let’s look at it from the perspective of 敷金 and it would be easier to understand. 敷金 is the money you pay up front when you rent the apartment so when you leave the apartment, the owner would use the money you paid to clean up whatever mess you made and return the remaining to you. This means the cleaner you leave the apartment, the more money you get back.
内装代 however is the exact opposite. When the previous tenant leaves, the owner renovates the apartment and pays for it first. If you like how the apartment looks and decide to rent it, you would pay the 内装代 which is about 30% of the amount paid by the owner. Since this money is already used by the owner prior to your rental, you do not get anything back when you move out.
So what happens if you accidentally damage something in the apartment when you leave? The owner would renovate it and the next tenant would pay for it via the 内装代. That’s it.