Supply teaching pays by the day but bills arrive by the month, and the school year leaves around thirteen weeks with no work at all. The calculator above turns a day rate into an annual salary so you can compare it with a permanent post. This guide covers the practical side: getting through the holidays, using your rights after twelve weeks in one school, and comparing agencies.
Budgeting through unpaid holidays
Take a supply teacher working five days a week for 39 weeks at £150 a day. That's £29,250 a year, and after income tax and National Insurance about £24,580. In a working week that's around £630 take-home, but spread evenly across all 52 weeks it's only about £473 a week.
The simplest way to manage this is to set aside about £158 from every working week's pay into a separate account, and draw on it during the holidays as if it were a weekly wage. It feels like a pay cut during term, but it means August and the Christmas break aren't a scramble. If your agency rolls holiday pay into your day rate, that rolled-up amount is exactly what the holiday account is for.
Tax helps a little here. PAYE works out your tax cumulatively over the tax year, so weeks with no pay don't waste your Personal Allowance: the unused part carries forward within the year, and your next payslips usually show slightly less tax than normal.
The 12-week rule
Under the Agency Workers Regulations, once you've worked in the same role with the same school for 12 continuous calendar weeks, you're entitled to the same basic pay and conditions as if the school had employed you directly. For a long-term supply placement, that can mean a significant rise, often to the point on the main pay scale your experience would justify.
The weeks don't have to be full-time, and some breaks, such as school holidays, pause the count rather than resetting it. If a placement is likely to run past 12 weeks, ask the agency in writing what your rate will be once you qualify. To see what a higher rate is worth, run both day rates through the calculator above. On the example above, a rise from £150 to £180 a day is worth about £4,200 a year after tax.
Pensions without the Teachers' Pension Scheme
Most agency supply teachers can't join the Teachers' Pension Scheme, because agencies aren't scheme employers. That doesn't mean no pension: agencies must auto-enrol eligible workers into a workplace pension and contribute to it. Contributions are usually much lower than the TPS, so if you mainly do long-term supply, it may be worth asking schools about fixed-term contracts that come with TPS membership.
Choosing an agency
When agencies quote different day rates, check how each one pays you. A PAYE agency deducts income tax and National Insurance directly from your pay. Some agencies pay through an umbrella company, which deducts its fee, employer National Insurance and other costs from the rate before your own tax is taken. The same headline rate can then produce very different take-home pay. Ask for an example payslip before signing up, and compare it with what the calculator above shows for a straight PAYE rate.
Keep records for your tax return
Most supply teachers paid through PAYE never need to file a tax return. You might need to if you also work self-employed, for example tutoring or exam marking paid without tax deducted. Keep a simple record of every placement, the agency that paid you and the amounts, along with any work expenses. If you've worked for several agencies in one tax year, check that each one used the right tax code, because overlapping codes are a common source of over- and under-payments.
Next steps
Enter your day rate and weeks above to see your annual take-home. If an agency pays through an umbrella, the umbrella and IR35 calculator shows how much of the rate disappears before your own tax, and the pro-rata holiday calculator explains how holiday entitlement works on irregular hours.