I was going to add this to an earlier locked thread but probably better to start a new one.

Looking at the IR website in prep for our 2021 returns, although the site itself is still clunky, it seems that they have made some basic but valuable improvements to the way they record and present our info. 

For example, they now show interest earned (say from a trading bank) and RWT deducted as monthly data - separated by transaction. I believe this is possible because IR now requires the banks to forward this info to them on a monthly basis, rather than at the end of the year as previously.

In addition, IR will now split this for you if it’s jointly earned - they split the income and the RWT. There’s a page where you can nominate the split ratios. In our case it was shown as 50/50 for Mrs Code’s and my joint account interest income (probably because that’s how we declared it last year) - it appears to default to 50/50 for two taxpayers but you can change it if you wish.

It also appears that they are doing the same monthly thing for wages/salaries and PAYE. As far as I am aware, none of this was in place 12 months ago. There may be other changes that I didn't notice.

It looks as though they haven’t yet got the same sort of handle on dividend income but hopefully that will come.