Should I be offering an annual salary or a per hour rate?
In adverts, quote it as annual salary gross, per hour gross, and per hour Net (based on taxcode 810L) if you like. Personally I prefer knowing the annual salary, as I've had non nannying jobs in the past so was used to that.
When agreeing the contract, agree a Gross salary either as per hour or annual.
Working out the above hours on a rate of £10ph net this equates to a salary (before tax and national insurance) of around £45,000 for 5 days a week ?
7:15 to 18:30 = 11:15
56:15 I make that if 5 days per week.
Do the timings include anything for handover/potential late arrival home?
Rounding up to 57 hours...
MrAnchovy's PAYE Calculator gives £39,985 Gross annual salary, if 10 net, taxcode 810L, no student loan. Employers NI: 4,486 So cost to employer (gross salary + employers NI) £44,471
So yes, £45,000 for just salary, cost of a payroll service (if using one) and a couple of hundred towards expenses. Expenses however will I suspect be more than that, especially if nanny uses their own car thus doing work mileage. Expenses I tend to estimate out at £5 per day, so £1200 a year. Mileage can vary, personally I do about 3000 work miles a year, so £1350
What would the nanny do the 15 hours a week my youngest is in pre-school? What should I expect them to do?
It won't be 15 hours once taking off travel time back from pre-school and to collect again. It's also not every week... it's only term time, so maybe 38 weeks.
Laundry is often a big ongoing task, changing bedding, general tidy around communal areas and child's room, baking cakes for the pre-school cake sale, picking up parcels from the post office, being in for the dishwasher repair person, tending to the veg patch, feeding the chickens, all sorts of things. They may if they get lucky get a 20 minute break to have a cup of tea/coffee.
Might be better to think about what things you Would Not ask them to do. They are a nanny rather than a cleaner, so cleaning the loo might be a bit too much to ask.
We would plan to take leave to cover most of the school holidays (and have family who could help out).
Costings are based on them working all year (with 5.6 weeks annual leave). If you want someone only to do term time, then that may limit who would apply for the job.
You can give more than the statutory holiday entitlement of 5.6 weeks, so if you can cover 6, 7, 8 weeks of the year... then giving that much holiday to your nanny would be a good perk. In exchange you would Restrict them in their ability to take holiday... such as it must only be during school holidays.
Would it be better to advertise for a Nanny/Housekeeper who could take on some other duties when the youngest is at pre-school
What duties do you have in mind? You could have a cleaner come in for a few hours a week to do the more deep clean stuff... then nanny could do the lighter housework.
When a job is advertised as nanny/housekeeper in my mind I see it being more of a cleaning job with some childcare... rather than a nannying job with a little deep cleaning. It's just perception though... it will actually come down to the job description as far as what duties are expected. You could run multiple ads with varying job titles but the same duties listed and see what happens regarding who applies.