There is no legal obligation to tell your employer that you are pregnant. It is up to you when you tell your employer that you are pregnant.
You are also not legally required to inform a prospective employer that you are pregnant, nor should you be asked in interview if you are pregnant.
There are reasons why it is a good idea to inform your employer of your pregnancy, such as requesting maternity leave. To take maternity leave, you should tell your employer by the end of the 15th week before the week your baby is due, when you give notice of your intention to take maternity leave and claim Statutory Maternity Pay. There is a sample letter you can use to give notice.
Why should I tell my employer?
There are advantages to telling your employer about your pregnancy earlier that then 15th week before your due date.
Once you have told your employer that you are pregnant, in writing, and there is evidence of any risk to you or your baby from your work, you must be given a health and safety assessment. We have a sample letter you can use to request a health and safety assessment.
You also have the right to paid time off work for antenatal appointments if you are an employee.
You have the right not to be discriminated against because of your pregnancy, but this can be difficult to show if you do not have proof that your employer knows you are pregnant. If you suspect your employer has guessed, it is a good idea to tell them in writing.
Many women wish to keep their pregnancy quiet at first, and if you tell your employer before you want other people to know, you must make it clear that you expect confidentiality.