From my experiments and searches through the guides and forum it looks like batch updates of tax codes is still not possible. Is that likely to change?
My use case: Some time ago, I found that the easiest way to get tax reports with transactions categorised the way I wanted was to create custom tax codes that used the same rate but had different names. For example, I had “VAT 14.5%” for transactions in ZWL and “VAT 14.5% (USD)” for transactions in USD. This worked well for my needs as it separated the ZWL and USD transactions on the report. However, I have recently had to abandon these custom codes so that my sales invoices conform to the requirements of the electronic signature device that I’ve had to have installed. All my VAT transactions are now assigned the “VAT 14.5%” tax code, regardless of the currency. I could simply stop using the custom codes and make them inactive, but for the sake of tidiness and consistency I would rather have the option to delete them and replace them with the standard “VAT 14.5%” code. I could manually change every transaction, but there are about 700 of them, so it doesn’t seem worth the time it would take.
(EDIT: Perhaps I’m confusing the original scope of this topic with my needs. I would like to batch update the transactions to which the tax codes are assigned, not the tax codes themselves.)