You must notify your employer of your intention to take maternity leave by the end of the 15th week before your child is due, and you must give your employer the information in writing if they request it. You can notify them earlier than this, and there are many reasons why this can be a good idea. For example:
All employers owe on-going duty to avoid risks at work to all women bearing age, including expectant and breastfeeding mothers and unborn babies. Afterall, in the early stages of pregnancy, many women may realise they are pregnant. But once the employer knows about your pregnancy, they will be able to discuss with you how to manage any risks that are specific to you, your job and working conditions);
you may want to talk through your annual leave arrangements with your employer. You will continue to build up holiday during your maternity leave but you can’t take holiday while on maternity leave, so it can be sensible to organise to take some of your holiday before you start your leave - or at the end of the leave, so that you can prolong the time at home with your baby once your entitlement to the paid element of maternity leave has been used up;
you may want to talk about arrangements for keeping in touch during your maternity leave. This is likely to be especially important during conditions of uncertainty and change, such as restructuring and redundancy. You will want to ensure your employer can reach you quickly and that you stay in the loop; and
you will need to tell your employer about your pregnancy in order to enforce your rights to time off for antenatal care.
The National Childbirth Trust has some helpful advice on telling your employer about your pregnancy.
You are protected under the law from being dismissed or discriminated against on the grounds of pregnancy or pregnancy related sickness once your employer knows that you are pregnant.
Your notice must state:
that you are pregnant;
the expected week of childbirth; and
the date that you intend your maternity leave to start.
Your employer can request that you give them a copy of your MAT B1 certificate (which either your GP or midwife will give you when you are about 20 weeks pregnant) which states the week that your child is due.
Your employer can request that the notice you give is in writing. This is probably good practice and will help limit the chances of misunderstandings later on, but make sure you keep a copy.
Once you have given notice of the date that you intend the leave to begin on, you can subsequently change your mind and change the date. In this case, you must notify your employer of the change at least 28 days in advance. If it's not reasonably practicable to give 28 days' notice you can give less, but you will need to show that you acted as soon as reasonably practicable.
Your employer must respond to your notice within 28 days, by giving you written confirmation of the date your maternity leave will end. The end date will always be a date 52 weeks after your notified start date, because all employed women automatically qualify for 52 weeks of leave, regardless of how long they have worked, their hours or how much they earn.
If you change your maternity leave start date, your employer should respond with a fresh notice confirming the new end date.
There is now the possibility of sharing your maternity leave with your partner under the Shared Parental Leave system, provided you both meet the requirements of the scheme. See workSMART's Shared Parental Leave section for more about the notice rules for Shared Parental Leave. Also, see SPLASH, a web portal devised by a group of legal advisers and charities, including Working Families and Maternity Action, providing guidance on the new Shared Parental Leave rights.