Self-employed digital contractors, including web developers, designers and consultants, pay Class 2 National Insurance once profits exceed £6,515 a year, at a flat rate of £3.45 per week, alongside Class 4 contributions charged at 6% on profits between £12,570 and £50,270, rising to 2% above that threshold. Both are calculated from total profit after allowable business expenses and paid through the annual Self Assessment return, with deadlines of 31 January and 31 July for those making payments on account. Contractors working through a limited company instead pay National Insurance through PAYE on any salary drawn, since dividend payments are exempt, though personal Class 2 and 4 liabilities can still apply if there is other self-employed income. A Small Earnings Exception is available for profits below £6,515, though foregoing contributions can reduce future state pension entitlement, which requires 35 qualifying years for the full amount. Checking a personal NI record annually helps identify and fill any gaps.