Set up the money right in 30 days.

Week 1 — Foundations

• Open a dedicated business bank account. Personal-account commingling is the #1 cleanup generator.
• Complete tax registration and understand which filings apply to you (see our tax calendar).
• Set up e-invoicing — required, and easier from day one than retrofitted.

Week 2 — Structure

• Pick cash or accrual basis (most very small businesses start cash; switching later is possible but noisy).
• Create a simple chart of accounts — ten to twenty categories you'll actually use, not two hundred you won't.
• Decide your invoice template, payment terms, and where customer payments land.

Week 3 — Rhythm

• Put every filing deadline in your calendar with prep reminders.
• Schedule a monthly 30-minute money review with yourself. Defend it.
• Start the receipt habit: photograph or forward every business receipt the day it happens.

Week 4 — Decide who does the books

DIY is fine at low volume if you're disciplined. The honest test: if you're more than two weeks behind by month three, outsource it — the cost of bad books compounds faster than the fee.