rule #1: give every dollar a job.

if you overspend, then you need to decide how you want to cover that overspending. if you assigned those dollars to groceries, but you overspent in your shopping category, then you need to adjust your groceries category to accommodate that spending. you need to make the conscious decision to say “well i guess i need to give some of my grocery dollars the job to cover the overspending i did in my shopping category”

the purpose of ynab is to make your budget reflect your actual dollars. a budget in a spreadsheet of just you saying “i need $200 for groceries, $1500 for rent, $100 for gas, $100 for bills, and $100 for shopping” is not connected to your actual dollars. that’s just you saying how much you need to cover your expenses.

however in ynab, you assign your actual real dollars sitting in your accounts the “jobs” they need to do to cover those expenses.

if you only have $1200 to budget with you need to decide which jobs you want those dollars to have. if you choose to put it all towards rent, you’re still $300 short on rent AND you don’t have enough money for groceries, gas, bills, or shopping. or you might decide to assign your $1200 to groceries, gas, bills, and shopping and the remaining $700 to rent and use your next paycheck to finish funding your rent category.

in summary: with ynab, your spending is attached to your budget, which means it’s attached to the jobs you gave your dollars. if you’re spending your dollars on a job you don’t give them… then which “job” are you taking dollars from?