"£30,000 pro rata" means £30,000 is the full-time yardstick and your pay is the fraction of it your hours cover. At four days a week that is £24,000 gross and £20,799.60 after 2026/27 tax and NI; at three days, £18,000 gross and £16,479.60; at half-time, £15,000 gross and £14,319.60. The table logic below shows why the smaller fractions keep a bigger share.
Every fraction of £30,000, taxed
Full-time £30,000 keeps £25,119.60 (16.27% deducted). 0.8 → £24,000 keeps £20,799.60 (13.34%). 0.6 → £18,000 keeps £16,479.60 (8.45%). 0.5 → £15,000 keeps £14,319.60 (4.54%). Each step down the fractions loses gross but sheds deductions faster, because the fixed £12,570 personal allowance and the NI threshold cover a growing share of the smaller figure.
The monthly view, which is what the bank sees
Per calendar month the same ladder reads: full-time £2,093.30; four days £1,733.30; three days £1,373.30; half-time £1,193.30. If your hours change mid-year, PAYE adjusts within a payslip or two: the code stays the same and the allowance simply stretches over whatever each period pays. A month that looks wrong is usually the old hours still in the payroll run, not the tax.
Checking an offer letter against this page
The letter should state the £30,000 FTE, your weekly hours, and the resulting actual salary. Divide the actual salary by £30,000 and you must get exactly your hours fraction; if you do not, one of the three numbers is wrong. Holiday should scale by the same fraction. 5.6 statutory weeks × 0.6 for a three-day week: and the per-hour pay rate must equal the full-timer's, which is the part-time regulations' floor rather than a courtesy.
Questions people ask about 30000 pro rata
Is £30,000 pro rata at 3 days a week a £30,000 job?
No: it pays £18,000 gross. The £30,000 is the full-time equivalent used to set the rate.
What is £30,000 pro rata per hour?
On a 37.5-hour full-time week the rate is £15.38 an hour at every fraction: the rate is constant; the hours change.
Why does half-time keep more than half the full-time net?
Because the £12,570 allowance does not halve. £14,319.60 is about 57% of the full-time net on 50% of the hours.