Know which is which
Fixed
Rent, insurance, phone, subscriptions, loan payments. Same-ish number, arrives on schedule, negotiated occasionally.
Variable
Groceries, fuel, utilities (partly), entertainment, clothing. Moves with choices and seasons.
Why it matters
Fixed costs are cut in a few phone calls a YEAR; variable costs are managed in small choices a WEEK. Different muscles.
The attack plan
Fixed: schedule an annual raid
One afternoon a year: re-shop insurance, call internet retention, audit subscriptions, check refinance rates. Gains repeat monthly with zero willpower.
Variable: set caps, not vows
A weekly grocery number and an eating-out number. Envelopes if a category keeps escaping.
Watch fixed creep
Streaming price bumps, insurance drift, 'temporary' subscriptions. Fixed costs grow silently unless raided.