Kazakhstan is continually removing bureaucratic barriers for visitors. You shouldn’t need a letter of invitation to get your visa it’s generally easy to obtain either en route or in your home country.
Our 30-day Kazakh visa was issued in one day in Tashkent for just $25 U.S. dollars on our European passports. Only the usual photocopies and passport photos were required.
Kazakh visas still need to be registered. This requirement is being phased out and if your visa has a large round stamp on it when you receive it then you are already technically registered before you even enter the country. You may also receive this stamp on your immigration card at the border.
Not all embassies and border posts have started automatic registration so if you don’t have the elusive round stamp you will have to visit an OVIR office to do the job yourself within 5 days of your arrival. The process is free in Shymkent and done in the same day. Avoid Almaty if possible where you pay about $15 U.S. for the pleasure of registering, which can take two or more days.
Some luxury hotels will register for you or it’s possible to employ a travel agent to handle the bureaucracy.
Once you are registered you’re free to enjoy Kazakhstan without the hassle of continually needing to re-register as in Uzbekistan.