The number printed on the front of the box is different because it represents the model series of the television.
For example, you purchased an XBR-43X800H, get it home, start to unbox it, and then notice X80 H on the box. Did you receive the right model? The answer is yes, your model is XBR-43X800H. The X80 H is the series that model belongs to.
To see your purchased model number, look at the label on the box. It may be located on the side or the back, and will list the model number as shown in the example below. Please note that the layout of the label may differ by model.