The perfect fit of a ski boot has little to do with your shoe size. A size that fit you a few years ago may not fit well at all these days. Boot companies have changed the shape of the toe boxes, taken some shell material away inside and made better fitting liners. In high school and college I skied in size 11 Lange boots. Since about 1980 I have skied in size 10.5 Lange boots. Today, when I ski in A Salomon X Max I ski in a 9.5 I could ski in a Lange 9.5 put might choose not to. You need to try boots on. You need not to reject the boot if it hurts a bit when you first slide in and buckle. Many boots today have custom moldable shells and liners and we have special machinery to remove hot spots. I would rather work on some pressure spots than try to shim a boot that has gotten big.  Here is a some technical information on boots from Atomic that I have added to in bold.

The message is come to our store, spend some time trying on boots and let us help guide you. We will also balance you in the boots which makes your skiing better and less tiring.