Director's National Insurance — is it really calculated annually, not monthly?

Yes, your friend is right. Company directors are classed as employees for NIC, but unlike ordinary employees — whose NIC is worked out on each pay period — a director's contributions are worked out on their total earnings for the tax year.

In practice, payroll software normally uses the standard annual earnings period method. Each time you're paid, it works out the NIC due on everything you've earned so far this tax year (salary plus any bonuses) and deducts what you've already paid. So with a small monthly salary and a bigger payment in March, your take-home in the earlier months is higher than an employee's would be — the £12,570 annual primary threshold is effectively spread across the year — and then a chunk of NIC lands in March once your cumulative pay crosses it. The total NIC for the year is the same whatever the timing; it's the month-to-month pattern that differs.

Two practical points: make sure your payroll software has you flagged as a director using the annual method (it goes on the Full Payment Submission), otherwise the figures will look wrong. And remember the company still pays employer's NIC on your salary, even if you're the only person on the payroll.

Yes — and Dasiy's summary of the standard method is right. The bit most people miss: there are two methods, and your payroll software lets you choose. The standard annual method ('AN' on the FPS) suits irregular pay: NIC is worked out on total pay so far in the tax year, less what's been paid. The alternative method ('AL') suits regular salaries: NIC is worked out on each pay period only, then reconciled at year end. The annual total is identical either way.

Worked example on a £1,500 monthly salary (£18,000 a year): total employee NIC is 8% of (£18,000 − £12,570) = £434.40. Under the standard method you pay nothing for the first 8 months, then £74.40 in month 9 and £120 a month after. Under the alternative method it's a steady £36.20 a month, trued up at year end. Same £434.40 overall; pick the pattern you prefer.

One pitfall: if you became a director mid-year, your software must use pro-rata annual thresholds from the 'week of director's appointment' — otherwise the numbers will be wrong. Contributions are still paid over after each payroll, even though they're calculated annually.