OP here. Thanks for the change of address advice. We are parting on good terms but makes sense to me.

Get the change of address form from the post office and have the 'old' au pair fill it out and sign it in front of you. This way you can be sure she's not accidentally changing your whole household's address. Then either watch her mail it in or mail it in yourself.

We're still dealing with mail (official government mail from her home country, I can read just enough of her language to know it's important) from an au pair we had go into rematch.

While it sounds like your current au pair is leaving under good circumstances, this is one thing I swore I'd do with all future au pairs, no matter how they leave.

We've had two au pairs and both have had their own computers. Do host families typically provide their au pairs with laptops to use for the year? I hadn't heard of that.

A few things to remember -

give the new AP the phone and computer right away so she can start making friends

make sure the room is ready for the new AP and move old AP out to another room

Call car insurance company and switch drivers

Have old AP take her to the Soc. Sec. office and bank

Have a going-away party for the old AP, and so new AP can meet her friends

Anyone have a checklist of things I need to be thinking about? We won't have any time gap between APs so need to be simultaneously thinking about wrapping up with the old and welcoming the new.

One piece of advice I got was to make sure that I keep a record of old AP's SSN.

It was only 1 yr ago that old AP arrived, but sadly my sieve brain can't remember all that I did to prepare/introduce new AP. Main things I remember is buying her a metro card, setting up her phone, and once she's here, bank account and SSN. And of course the nerve-wracking first few days of driving practice :