You can legally charge interest and compensation on late B2B invoices

Under the Late Payment of Commercial Debts (Interest) Act, if another business pays you late you can usually claim statutory interest of 8% above the Bank of England base rate, plus fixed compensation of £40 to £100 per invoice depending on its size. Most small businesses never use this. Simply mentioning it helps: add a line to your terms and invoices saying you reserve the right to claim statutory interest and compensation on late payments. It only applies between businesses, not to consumers. You don't have to use it on every client, but knowing it exists changes the conversation when someone is 60 days late.