to want to pay off the mortgage instead?

In your op you said you wanted to enjoy yourself. Even though the schools aren’t good,

Mortgage, definitely pay off a chunk of the mortgage. It's the first thing I would do if given a chunk of money as a secure home is very important and will allow much more freedom with your income each month (to spend on things like school fees if you so choose).

Doesn’t sound like that at all and undermines real abuse that is control . They key fact that’s missing here is what was said about why it was gifted.

It wasn't clear you are a single parent. In that case yes the mortgage. If you get injured and unable to work you'll be grateful you did

Well yeah but you do it over 3 years..

We went private for secondary but then fees were £11k but now they are £18k per annum and when VAT gets added on it will be a scary number to commit.

£100k is not enough even if you just did Yr7 to Yr11. You have to add on transport, lunch, extracurricular, trips, exam fees etc Plus plenty of private students get tutoring as well ( I know as a tutor independent kids every year)

You must have had some idea of why they were giving you the money? No one hands over £100,000 without some conversation.
They made a presumption why did they presume that?

Yes if it's a 'gift' you can do what you want with it. But if you know it's an extremely generous gift meant for a particular purpose important to those that gifted it, it seems extremely self aborbed to ignore their wishes and just do what you want.

You aren't sending a toiletry set to the charity shop, it's £100,000 of their money they want used for education.

I think if you know they don't want you to spend it on the mortgage the best thing to do would be to give it back and say: thank you for the kind gift but I don't want to spend it on school fees so think you should have it back so you can spend it as you wish.

If they are otherwise reasonable people, have a conversation with them about it.

They may be assuming private school fees are still in line with what they were 25-35 years ago, when they may have paid it for you or looked into it. Or they may looked up the base fees without realising the extras needed on top, that they increase annually, that they increase by year of school, likelihood of VAT etc. (From someone whose child has just finished private school and not a moment too soon...)

Doing the sums and showing them that their gift will only pay for eg 2-3 years as a pp said may help to set things in context.

It also really depends on the child you have, the state schools and private schools available to you locally, and whether the difference is worth the cost. In our current area, private prep or state primary (if you can afford a house in the best catchment - £1m+) and state grammar is the best and most cost effective option. In my home area, it's state primary and private secondary (because the local primaries are great but secondaries are not). There's no one size fits all IMO.

Investing the money for your child's university (if they go) and/or towards a house deposit may be a better use of it. Or paying off your mortgage earlier to allow you to build up similar savings for them.

I think it was unfair of them to give you the gift so you could use it for school fees, but not to actually tell you that. You’re not a mind reader. If they wanted to pay for school fees then that’s what they should have offered to do, so in that sense YANBU.

I do also think that being mortgage free by 45 is unnecessary though. Obviously it would be nice and but I wouldn’t personally prioritise it over other spending.

Pay off the mortgage early - it will give your family so many options. Don't waste the 100k on private school. If I had paid for my children's education I would be so resentful, when you can have it for free!

Use it to pay off half the mortgage and then pay what you are saving into an investment account for DD.

Private school at primary age is silly.

No doubt in my mind - chuck it at the mortgage. You’ll save a fortune in interest.

You’ll save way more on mortgage compound interest if you pay down the mortage.

Do you want to send her to private school?

Assuming you do, and you only want to send her from secondary level, your wisest move is to pay down the mortgage, and simultaneously start saving into a high interest rate account.

£100,000k off your mortgage on a 10 year fix at 5% could well save you compound interest of £30,000

So I would reduce my mortgage and use the savings to put into long term savings for school fees.

@Mochipuff

Put £50K in high interest isa, let it grow til DD about to start secondary, and use it for private school then?

Wait, is the isa limit £50k now, I thought it was £20k

Sound like your parents are trying to control you OP and your daughter. I would pay off the Mortage then say that you are using that more to save towards school fees. Surely that is much more tax efficient

The key question here is what did the parents say when they gifted the money. The op is strangely silent on this. There is no way this is a surprise. As such, it would appear she was gifted the money for her kid and used it for herself, as she said, so she can enjoy herself, even though the schools aren’t great. Hence why she feels shit.

Could you say to your parents that you'll pay off the mortgage but put what you're saving on the mortgage into an isa that could potentially be used for private secondary school in future.

You don't know what your local secondary will be like in seven years, it could be great and then the money saved could be used to help DD at university or with a house deposit.

My DC are thriving in state schools so I'm very pleased we didn't stretch ourselves to pay for private.

Nice problem to have though, generous and wealthy parents.

I would put it all towards the mortgage, no question.

I would 100% be doing your original plan OP. Then you will hopefully be in a position to help your DC through Uni /setting up as an adult plus afford some amazing life experiences together along the way.

Your parents error in not stipulating what is was for or indeed giving enough for all private fees.

Seeing as you earn a good salary, why don't you use £50K to pay off mortgage now.

Put £50K in high interest isa, let it grow til DD about to start secondary, and use it for private school then?

Your mortgage payment will be less, you'll feel more secure in your housing and have a nice lump sum waiting for DD's education.

If the state school goes tits up it sounds like you have enough to pay to switch her to private anyway regardless?

Why are people discussing the merits of paying off the mortgage against private education?

If the grandparents gave her the money without any stipulations then the OP can use it on drink & drugs if thats what she fancies.

The issue is the GP gifting money to the OP with or without stipulations or at least a very clear conversation.