It used to be 21%, but now it's too little. You don't need a notary office to notarize it. You can redeem it directly. You can also redeem it at the local tax authorities where you sell it. It's especially convenient. Occasionally, the boss will blackmail you with a big prize, so you can redeem it at the local tax. Don't make a noise when you scrape out the big prize. Don't let the boss know that the small prize will be cashed on the spot.