As we have talked about on these boards, for a period of time our financial arrangement had been working reasonably and I did not see a reason to change it. That time may have arrived for the reason that I need more autonomy and privacy from W’s input and interference.
As you answered, no real need to discuss with W.
If you want more financial autonomy, then get it.
And of course, it is good practice to reflect and ensure, before implementing a new major change. (You mentioned this as well. )
Has W been upholding her share/obligations? If so, what would be gained by formalizing it? Realize, your gain is not from the financial side. It’s autonomy and privacy, which sounds quite reasonable.
Are these financial changes things you would continue if you and W were to reconnect? If yes, then it is a good indicator that you are doing this for you, and not some attempt to get a reaction from W. (By the way, if my XW and I ever patched things up and got back together, I’d keep my finances separate for a good long while. A very long while.)
I’d not give W an ultimatum regarding this. (I spoke a bit of ultimatums on Peter’s thread.) You’d more just inform W of what you are doing going forward regarding the joint monies and bills.