You must notify your employer of your intention to take Ordinary Maternity Leave by the end of the fifteenth 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 may find it helpful to do so to ensure that your health and safety rights are observed, and that you have time off for antenatal care. You are protected under the law from being dismissed or discriminated against on the grounds of pregnancy, once your employer knows that you are pregnant.
Your notice must state:
Your employer can request that you give them a copy of your MAT B1 certificate which you will be given by either your GP or midwife when you are about 20 weeks pregnant and which states the week that your child is due. Your employer can request that all the notice you give is in writing. This may be good practice in any case to avoid any problems in the future, 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 vary the date. In this case you must notify your employer of the variation at least 28 days before the new date begins, or if this is not reasonably practicable, as soon as is reasonably practicable.