Maternity leave date?

[NeedMoMoney]

Not aibu, just the usual posting for traffic.
I sent my matb1 form to the relevent person at my work as soon as I got it (received it at my 25 scan) phoned said person and they said all I had to do was send it in,
now hears the pickle I'm in. No one has asked me when I'm planning on taking my leave from, im now 28 weeks so still got a while to go but as I'm having twins they said it could be as early as 37 weeks if not sooner so looking likely begining of october. This is my first pregnancy so Im not sure if I have to ring them up and let them know (thinking latish September, just to have a few weeks to get things ready) but how late can I let them know?
I know I can ask them at work but was just wondering if anyone here will know if I've left it to late and If they can say no you should have let us know sooner,

Thankyou for any advice and anyone that's read my ramblings ☺️

My company need 8 weeks notice prior to your first day of leave and the same for our return dates. Also if you are off sick with anything pregnancy related from 36 weeks it triggers your maternity leave to start. Not sure if that is standard though.

You should have told them when you want to start your leave (in writing if they ask for it) by the time you are 25 weeks pregnant

I definitely hadn’t settled on a date by 25 weeks pregnant. I went off last year and think I agreed it about 4 weeks in advance, obviously they knew within a week or 2 based on due date.
I would just ask HR tomorrow.

www.gov.uk/maternity-pay-leave/how-to-claim

Statutory Maternity Leave

At least 15 weeks before your due date, tell your employer when the baby is due and when you want to start your maternity leave. Your employer can ask for this in writing.

Your employer must write to you within 28 days confirming your start and end dates.

My work has a form i had to complete as well as matb1 that states start date and planned end date, they then write back confirming mat period and company mat pay

Thankyou for all your replys!
When I sent my form in the lady that dealt with it never asked me when my planned date for leaving was and hasn't been in contact to ask, as it's my first I have no clue on how to do any of this, so just freaking out a little now! I'm definatly going to ring tomorrow when I get into work! 😊