Nup, not essential. I was given a manual one and have access to an electric one but hardly use either. Especially in the begining, you just want to focus on getting breastfeeding working without worrying about pumping as well. If you do need one (cos of a prem baby or similar) then you can buy one or hire one pretty quick. THe ABA hires and sells pumps and you get a discount if you are a member. If you join up you also get a discount on their breastfeeding classes which are also really worthwhile.