"It's not like they'll simply 'email' me a counter - they'll want to know why I'm leaving, whether there's something they could do to try and keep me here, etc. There's a lot of discussion that they'd want to have before doing a counter offer, and the point of my question is that I want to find a non-rude way of asking them not to waste their time on that."
Here's your resignation letter,
"Dear team,
I am hereby resigning from the position of [Current position] at [Company]. My final full day will be Wednesday July 3rd.
My plans and location from Thursday July 4th are settled.
Thanks for the great experience at [Company]. Please let me know every way I can ease the transition and ease any paperwork.
Cheers, F. Attie
It's a case of you just have to deal with it, unfortunately. DON'T say anything really explicit like "do not send me a counter offer" or "no discussion entered in to".
The closest you can get to being rude and direct is this language:
My plans and location from Thursday July 4th are settled.
or
My plans and location from Thursday July 4th are settled, thank you.
As my shrink says, "you can only be responsible for you". If some person at the organization wants to walk up to you and start talking about it - that's not you., that's them.
Just politely say "Ah, my new plans are settled from the 4th, thanks."
Email, same response. Again the closest you can get to being rude/direct is
My plans and location from Thursday July 4th are settled.
Hope it helps!