Disclaimer
This is not tax advice. Tax law changes. Hire an accountant who knows your country’s rules once you’re earning over $1500/mo regularly.
The general principle
You owe tax in the country where you are tax-resident. For most Africans that means your home country. If you work for a US/EU company, they typically do NOT withhold tax — you do.
Nigeria
Register a business (small business registration is easy) — paying yourself a salary as a business is often cleaner than personal income tax on freelance earnings. Talk to a chartered accountant before you make $5k/mo.
Kenya, Ghana, South Africa
Each has a turnover-based tax for freelancers + a personal income tax bracket. The threshold for hiring an accountant is roughly the same: once you’re earning USD consistently, it’s worth $50/mo to keep your filings clean.
Common mistakes
Not filing because "they won’t know" — your bank does report to tax authorities, eventually. Mixing personal and business accounts. Assuming your US employer’s 1099 covers you — it doesn’t.