What do I need to know before moving to Mumbai?

"The best advice was to bring a great mattress; Indian mattress are not like ones at home. Bring your vacuum cleaner; I have a Kirby so it really hurts that I left it behind. Choose a very good moving company; I thought mine did ok until I heard war stories from other expats (I did send an apology). Get your PAN card ASAP; you can't sign a lease agreement without one. Be very clear to what you want and make sure the settling in people stick to your guidelines as they will waste your time showing things that don't fit; I knew what was on the boat and needed 4 bedrooms and they kept showing us 3 bedroom flats. I knew that I wanted to be close to Indian culture without sacrificing access to expat shopping. I did not want my husband and children to spend more than one hour on commuting. Ask Indians for advice; so many freely helped us navigate the waters. They were our saving grace," remarked another expat who made the move to Mumbai, India.

What do I need to know before moving to Mumbai?