Tax namekey changing

Hi,

You can. Go in the "manage tax rates" button via the System>Taxes menu and create a new tax rate with the namekey you want for your tax rate.
Then, edit your tax rules and change the tax rate to the new one. That way, new orders will use the new tax rate.
Change the tax rate namekey in the database is not a good idea as HikaShop relies on the tax rate namekey when displaying the taxes in the invoice and the backend/frontend as its that namekey which is stored in the order.
So you would have to change the tax namekey in all the orders in the database and it's not easy as the data is serialized in the order information.
Also, you can use translation overrides to change the text.
I suppose you could have a translation override like that:
BTW_HOOG="My custom text"
www.hikashop.com/download/languages.html#modify

Hi,

Well, even now you can use a translation override to change it. I think that's the best solution here.

Really changing the tax rate name would require modifying all the orders using that tax rate. If you have thousands of orders, it's impossible to do without a crash of PHP on hosting with small resource limitations. And we want to avoid a crash where you would have some orders modified and some not. So that's why we disallow it.
And if we would allow you to change it without changing it in the orders, you would also loose your satistics so that wouldn't be a solution either.