What if one person wants a luxury hotel and the other can't afford it?

The higher earner should pay the difference for the upgrade, or the group should compromise on a mid-range option that fits everyone's budget.

Should we split groceries if we have different diets?

Split communal staples (milk, bread, fruit) evenly. If one person buys expensive dietary-specific items, they should pay for those separately.

How do we handle 'surprise' expenses?

Agree beforehand that any individual expense over $50 requires a quick 'group approval' text before being paid.

Fairly split travel costs when income levels vary

Use a percentage-based contribution model where each family member pays a portion of the total trip cost proportional to their income. Alternatively, assign specific high-cost items like flights to higher earners and lower-cost items like groceries to others to keep the burden equitable.

Establish a total budget upfront. Create a shared spreadsheet before booking anything. List every expense: flights, accommodation, car rentals, activities, and a daily food fund. Agree on a total 'trip cap' that everyone feels comfortable with.
Calculate income ratios. If family members have significantly different incomes, use a ratio. If Member A earns $100k and Member B earns $50k, Member A pays 66% and Member B pays 33% of shared costs. This maintains the same relative 'financial pain' for both parties.
Use a shared expense app. Download an app like Splitwise or Tricount. Log every purchase as it happens. These apps allow you to set uneven splits (e.g., split a restaurant bill 60/40) so the math happens automatically without awkward conversations.
Tier the responsibility. If ratios feel too clinical, assign categories. The higher earner pays for the rental car and the Airbnb reservation. The lower earner covers grocery runs, gas, and casual coffee stops. Check in halfway through the trip to ensure the totals are still balanced.

What if one person wants a luxury hotel and the other can't afford it?: The higher earner should pay the difference for the upgrade, or the group should compromise on a mid-range option that fits everyone's budget.
Should we split groceries if we have different diets?: Split communal staples (milk, bread, fruit) evenly. If one person buys expensive dietary-specific items, they should pay for those separately.
How do we handle 'surprise' expenses?: Agree beforehand that any individual expense over $50 requires a quick 'group approval' text before being paid.