Decide which house the costume lives at, before Sunday night
The costume problem almost never happens on the weekend. It happens at eight o'clock the night before, when the striped top is at the other place and nobody is driving anywhere. So send one message now and keep it boring. "Parade is Wednesday morning. She wants to be the wombat. Costume lives at yours for the week, I'll send her school shoes back Sunday. Anything you want me to grab?" One house owns it. The other house owns nothing and does not need to hold anything in its head. If your child changes houses mid-week, the costume travels in the school bag, not the overnight bag. The school bag is the one that always arrives.
Pick the character on a call, not in a shop
Choosing the character is the part a parent away for work can genuinely do, and it is better done ten days out than on the drive to Kmart. Ask the child to bring three books to the call and hold them up. Then ask the question that actually decides it: "Which one do you want to be at lunchtime, not just in the photo?" Anything with a mask, a cape that drags, or a helmet gets ruled out by that question on its own. The same call is where the making gets divided up. One of you works out how to fold cardboard ears. One of you owns the brown jumper. Neither of you is at the shops at nine at night.
Costumes you can build from clothes both houses already have
Grey or brown trackpants with a matching jumper is a wombat, a koala, a possum or a bilby, depending entirely on the ears. Ears are a strip cut from a cereal box, stapled into a headband and coloured in with a texta. White school shirt, grey jumper, any tie, and round glasses bent from a pipe cleaner is a wizard. Green top and a red beanie is the caterpillar, with paper circles for the fruit if you happen to have twenty spare minutes. Bucket hat, shorts, bare feet and a paper bird under the arm is a beach book. Pyjamas and a torch is roughly half the picture books ever written. And the ten-minute one. Cut the front panel off a cereal box, tape a sheet of paper over it, write a real title and the author's name in fat texta, and hang it around the child's neck on a bootlace. The child is the book. It is a costume about a book, which is the actual brief.
Keep the same four plain things at both houses
The reason two-house Book Week goes sideways is that the good clothes are always at the wrong address. The fix is that neither house keeps a costume, and both houses keep the same four plain things: one white shirt, one brown or grey jumper, a beanie, and a roll of masking tape. With those four items in a drawer at each place, any morning is recoverable from either address. It also means the child is never the one carrying messages about what is where.
Ask about the parade photos on the Monday, not on the morning
Schools generally run a permission list for photos and video, because other people's children end up in the frame. That is why a request made at 8:45am on parade day tends to get a no, and a request made on the Monday often does not. Email the teacher early in the week and ask for the thing that is actually gettable. "His dad is on a swing and gets back Saturday. If the parade is going up on the school app, could you let me know, and if not, would you mind taking a ten-second clip of just Archie as he comes past?" Ask another parent at the gate as a backup. A clip beats the parade itself in one specific way. A parade lasts four minutes and you cannot hear a thing over the PA. A clip can be watched at nine at night after a shift, three times over, with the child on the other end of the phone explaining who everyone else is dressed as. That version keeps.
The book underneath the costume
Australia does turn out for reading. A separate event, the Australian Library and Information Association's National Simultaneous Storytime, recorded 2,204,658 registered participants across 16,632 locations in May 2025, all reading the same picture book on the same morning. The costume is a reference to a book. If nobody reads the book, it is an outfit. So once the character is picked, that title becomes the week's bedtime reading in chunks of a few pages, and the parent who is away is the sensible one to hand that job to. A donga at eight o'clock is a quieter place to read a chapter than a kitchen in the middle of dinner and the bath. Holding a paperback up to a phone camera is fiddly. That is the specific problem StoryLink was built around: a video call where both ends have the same picture book open, and turning the page turns it on the other screen, with both faces still on. The calls and the library of 333 books are free. Other apps do a version of the shared page too, so have a look around. What we will say for ours is that the books are written and drawn here, and one of them is about bin night with Pop.
If the morning goes wrong anyway
Sometimes the costume is at the other house and there is no time, and that is a Wednesday, not a verdict. School uniform plus one prop plus a book under the arm is a costume. A hat and a book. A tea towel as a cape and a book. Give the child the sentence to use so they are not improvising in the line-up: "I'm the kid from the treehouse book." Say your own part flatly on the way in. "We didn't get to the costume, so today you're the kid with the book." No apology speech, no build-up. It lands as a fact about the morning, which is what it is.