Upgrage 411 to 411A is it possible

HI,

Is it possible to buy a level 4 Licence and upgrade an RB411 to use as access point?

It’s not possible to upgrade license. You can buy new one.

Yes you can buy a new license and upgrade a lower device if you want to.
http://wiki.mikrotik.com/wiki/Manual:License

But for the price it’s usually worth it to just buy a new board that has the level that you want.

I pay for abou 33$ for level4 with tax(VAT).

thanks guys.