When Should I Tell My Manager That I’m Expecting A Baby?

You should tell your manager as soon as possible but no later than 15 weeks before the EWC. You will receive a MATB1 from your midwife or GP once you are at least 20 weeks pregnant. To find the 15th week before the EWC, find the Sunday before the due date (unless your baby is due on a Sunday, in which case use the due date), and count back 15 weeks.