store up trouble for (oneself)

To cause problems or difficulties for oneself in the future by not preparing or acting properly now. I'm telling you, you're just storing up trouble for yourself if you don't tackle the paperwork for all this now. She didn't deal with the troublesome employee at the time, and she ended up storing up trouble for herself down the line.

store up ˈtrouble, etc. for yourself

have problems in the future because of things that you are doing or not doing now: If you don’t deal with the problem now, you’ll be storing up trouble for yourself later.