Change the expense split

For all new expenses

On the web: go to Shared, then Shared expenses. Pick a preset from 30/70 to 70/30, use the slider, or type your share exactly.

On iPhone: go to Shared, then Plan, then Shared expenses. Use the slider or a quick pick, or enter your share exactly.

The new split applies to expenses logged from then on. Expenses already logged keep their split.

For one expense

When you log an expense, change the split for that one before you save it. On iPhone, tap Change. On the web, move the slider.