The earliest that you can start your maternity leave is 11 weeks before your expected week of childbirth, which is when you are about 29 weeks pregnant. To ensure that you get all your rights, you should use the due date given on the MAT B1 pregnancy certificate that your midwife or GP will give you.
In order to work out when the 11th week before your expected week of childbirth falls, you should find the Sunday before the date on which the certificate states your baby is due (or the due date itself, if it is a Sunday) and count back 11 Sundays from that date. The earliest date on which you can start your leave is that Sunday. As long as it does not fall more than 11 weeks before your baby is due, it is generally up to you when your maternity leave begins. You can even choose to work right up to the date the baby is born.
You should note that the start of your maternity leave might be triggered automatically if:
- you have a pregnancy-related illness or absence in the last four weeks of your pregnancy. In this case you must inform your employer that you have an illness that relates to the pregnancy and they can insist that you start your maternity leave even if you are off sick for only one day. However, many employers will allow you to carry on working until you had planned to start your leave, especially if you have only been away for a short time; or
- your baby is born before the day on which you were planning to start your leave. In this situation, your leave starts automatically on the day after the day of the birth. You must notify your employer as soon as reasonably practicable that you have given birth and the date of the birth.
Having been notified of your intention to take maternity leave and the date on which it will begin, your employer must give you notice of the date that your maternity leave period shall end. Your employer must provide you with this information within 28 days of you informing them of the date that your leave period will start on or has started on.