Very small businesses fall under a flat or lump-sum regime based on annual turnover, while larger SMEs move to a simplified or real regime with proper accounts. Knowing which bracket you are in determines everything else.
VAT registration becomes mandatory once turnover crosses the statutory threshold, and registered businesses must issue electronic invoices through an approved EBM device and file returns monthly or quarterly.
Other common obligations are PAYE and RSSB on salaries, withholding tax on certain payments, and the district trading licence. Filing and payment run through the RRA online portal; late filing penalties accumulate quickly.