Kids off in term time. A quick question! The fine!

Yes before I start I know I chose to have kids, all teachers will hate me, I’m a middle class mard arse etc etc, however.
I’ve requested for three days off for both kids at the very start of the new term, so basically an extension to the summer holiday. The reason being is its my mums 60th and she’s going away. My nan is also going to be there. This will probably be the last holiday we will all get together blah blah. My mum knows not of the plans.
Child 1 at junior school has been refused, head said he’s sorry he doesn’t mind at all due to 100% previous attendance but will have to fine us. Child 2 at senior school ok’d, not authorised but no fine. Who has the say on the fine and who gets the cash?

[teacher mode] crappy time to miss school[/teacher mode]

[realist mode]you’re way too honest for your own good – have you not taught your kids how to cough meekly and look a bit feeble on returning from 3 days ‘ill’ – it’s an important life skill [/realist mode]

No idea about the fine business – are they both lea run or is one an academy/free school etc?

I know loads of folk who’ve done it but asking the kids to lie doesn’t sit well with us. However laddo gladly tells people the birth mark on his arm is actually a burn he received whilst saving some small children from a fire 😆
Back to the actual days, the kids have always reported back they do sod all in that first week back.
It’s not a done thing yet as we are still weighing up the whole affair and haven’t booked flights etc. However it’s my mum and nan who I know would be over the moon if we suprised them.