Interhome should have a key pickup point in Bayonne itself, for the houses in Bayonne. Going to Biarritz to check in and pick up the keys was a bit of a hassle. On the other hand the guys at the office were very nice and understanding and managed to make the key drop and check out easy.
Do check for the basic emminites, bed sheets and toiletries as they are not included. In my opinion, it should be provided and the cost should be included in the bill itself, while booking.