Almost every business plan I've reviewed gets one thing wrong: it accounts for the costs people expect and misses the ones that show up anyway.
People budget for equipment, a website, maybe some marketing. What gets missed is the slow ramp — the months where expenses are real but revenue is still building. It's licensing and insurance that turn out to cost more than expected. It's the software subscriptions that quietly stack up. It's the fact that your first few months of revenue often go to fixing mistakes made while you were still learning the business, not into your pocket.
My advice is the same one I give in every consulting conversation about startup costs: whatever number you land on, plan for a cushion beyond it — enough to cover three to six months of expenses with little to no revenue. It's not pessimism. It's what turns a rough first year into a survivable one instead of a business that folds before it had a real chance to work.
