Female couples now have the same rights as heterosexual couples when registering the birth of a child conceived as a result of fertility treatment.
From Tuesday 1 September, changes to the Registration of Births and Deaths Regulations 1987 mean female civil partners who use fertility treatment to conceive a child will be treated in the same way as married couples, with both female parents' names able to be included on the birth certificate.
In addition, female couples not in a civil partnership but receiving fertility treatment may also be registered as parents in the same way as unmarried heterosexual couples.
In both cases, providing relevant conditions are met, the female partner of the mother can be recorded as "parent" in the birth or still-birth registration and on any certificates issued.
Before this change, the mother's female partner could not be registered as a parent.
The changes to the regulations were approved by Registrar General James Hall earlier this year following Royal Assent for new parenthood provisions contained in the Human Fertilisation and Embryology Act 2008. The Act's provisions only apply to female couples who have fertility treatment on or after April 6 2009.
Home Office Minister Lord Brett said:
"This positive change means that for the first time female couples who have a child using fertility treatment have the same rights as their heterosexual counterparts to be shown as parents in the birth registration.
"It is vital that we afford equality wherever we can in society, especially as family circumstances continue to change. This is an important step forward in that process."
Stonewall's Head of Policy and Research Ruth Hunt said:
"As the law improves to provide further equality, knowing your new rights will help people make full use of the services they're entitled to. And, if discrimination occurs, the same knowledge can help them demand fair treatment.
"Now lesbian couples in the UK who make a considered decision to start a loving family will finally be afforded equal access to services they help fund as taxpayers.