Xero is the leading cloud accounting platform for UK small businesses. It handles invoicing, bank reconciliation, expense tracking, and Making Tax Digital (MTD) compliant VAT reporting. Its integration ecosystem (700+ apps) connects with payment processors like Stripe and GoCardless, payroll tools, and practice management software. The Starter plan (£14/month) covers up to 20 invoices. Xero also has a large UK accountant community, making it easy to find a certified partner.