To be unhappy with this hybrid work policy?

As your DS is 11, I would keep quiet about this. If it ever did happen then either have a discrete word with your line manager- I suspect if you go in as required normally they won't make you make up the time, or as your DS is 11 and he should be ok as a one off to be home alone for a couple of hours at that age, and certainly should be ok on a semi regular basis once he is in secondary school.

We’re supposed go in twice a week but the reality is that those with caring responsibilities make it work for them and the rest of us aren’t bothered as we’ve, mostly, all been there. Also, some weeks we go in 3 times and some weeks one. I think hybrid my definition is supposed to be flexible. Generally as long as the work is getting done and no-one taking the piss then no one cares.

I do think my team work better when we get to be physically in the same place though so I can see why companies are making people go back.

That’s what I do too. I pay for 4 days of wraparound and that allows me to be flexible for the 2 days I need to be in the office. It’s not your employer’s fault that your childcare arrangements are different. You need to make the arrangements work for the job you have. My kids are not wild about wraparound care either (who is?!) but that’s what it takes for me to do my job so I do it.

Can your son just let himself in if this happens? Sounds super rare and you have a great deal already being allowed to flex your time and still do school pickups. We aren't allowed to be working while caring for our children so my kids have after school club even on the days we are home.

HMRC?

Our place is dictating in office 2 days per week. I'm only 0.75 FTE (spread over 5 days) so my LM is happy for me to go in 1 day and is very flexible. Would never demand what your employers are talking about

My Office said 2 days a week in the office. Which was fine but I only did 3 days! So proportionately it was a lot more significant to me than my colleagues.

In principle our office is like this - basically you need to make 40% across the month so if you miss a day, you will need to make it up.

In practice, most line managers turn a blind eye to it for someone who is otherwise a good worker and for whom it's an occasional issue.

It's more in the policy so that where you have someone repeatedly taking their office days off sick but mysteriously always being fine for their WFH days, you have a way to push them to sort it out.

In your situation, I would just give your 11 year old a key for the odd day this happens

So frustrating OP. Arbitrary requirements and rules dressed up as being “flexible” when the reality is they aren’t. My office bought in similar rules (having been recruited not 1 year before on the basis office attendance was only once every 6 weeks). I was “called out”
for leaving on an office day before 5pm. I quit. The afterschool club finished at 5.30 and the commute was an hour, I was supposed to work “flexi-time” allowing me an early log in and earlier log out.

I've never seen the jobs come back, what sector do you work in? A lot of places have stuck with Eastern Europe, some have moved on to the Philippines because it's cheaper than anywhere else.

They have to do it or it creates a loophole where people are off sick for a day or two at full pay to avoid going into the office at all.

Civil service?

@HybridWorker did the company not enforce the two days before? when your son did not walk home from school, who collected him and dropped him off?

Just tell them you can't be flexible about what days you come in and will need certainty for childcare reasons. I can't see a downside for the company or team knowing exactly which days you'll be there.

Whether it's 'fair' or not is a different matter but my previous employer took a similar stance to this. I submitted a formal flexible working request and was rejected. I went on to appeal it and was also unsuccessful. I wasn't able to make the hybrid offering work so I found a new job and left.

Why do you have to make up hours if you are out sick.? Do you have to make up hours if you are sick on your wfh days?
I can understand if you booked every Friday as a stand alone holiday day when it was an office day or even if you are only ever sick on an office day but other than that not sure why you should have to make up time in office.

I think you are over worrying. How many company days and sick days will there be in reality? And on average 3/5 of them will fall on days that you are at home anyway.

I'm sure you can make ad-hoc childcare arrangements for the very odd day that there is an issue, or, on the basis that your DC is 11, just let him be at home on his own.

Can you get a day or two in hand eg going in over holidays when he’s in childcare or other parent around. Then you are always ahead.

I think your gut to sit tight is best. It’s probably not going to be enforced eg if you’ve been off sick then often it’s best to wfh when back so you don’t pass it on or aren’t 100% after an op but ok to wfh.
Or offer to do 2 half days if they insist due to no childcare.