In May, I’m flying from Florida to Seattle with my parents and my daughter, and from there we’re driving up to Vancouver for a few days before circling back. Five days, two countries, one car seat, three adults, one very excited 4-year-old.
I thought booking the rental car would be the easy part of this trip. It was not the easy part.
So I’m going to write down what I learned, partly so I can come back to it before May and partly because if you’re trying to do the same trip — fly into Sea-Tac, drive across the Canadian border, come back — the internet will give you forty different answers and you’ll close your laptop more confused than when you opened it.
Here’s the version that’s actually true.
The cheapest realistic option is Costco Travel
I priced this out across the rental sites, the aggregators, and Turo, and the number that kept winning was Costco Travel. Not by a little — by a lot. There’s a comparison floating around where the same rental was $290 through Costco and $677 booking direct. Same car, same week, same airport.
A few things make Costco Travel weirdly good for this specific trip:
It’s usually 10–25% under the rental companies’ direct rates, sometimes more. I don’t fully understand the magic, but it’s been true every time I’ve checked.
Free additional driver. Costco includes a second driver at no charge with Alamo, Avis, Budget, and Enterprise. That means I can put one of my parents on as a backup driver without paying the daily add-on fee, which adds up fast on a 5-day trip.
No Canada surcharge. This was the one I was most worried about. Alamo and Enterprise at Sea-Tac both let you take the car into Canada with zero extra fee, as long as you bring it back to the U.S. (which we are). They’ll just give you a Canadian Non-Resident Insurance Card at the counter — it takes about 30 seconds and it’s free. You hand it over at the border if anyone asks, and that’s the entire “international” part of the rental.
I’m 27 with my own credit card, and we’re bringing our own car seat, so I’m dodging the two big surprise charges that wreck most rental quotes: the under-25 surcharge ($25/day) and the rental car-seat fee (which is around $13–15/day at Sea-Tac and apparently sometimes the seat itself looks like it’s been used as a chew toy).
For three adults plus a car seat plus five days of luggage, I’m booking an intermediate — basically a Corolla or Sentra class. Compact only saves a few dollars and immediately gets cramped, and full-size adds $5–15/day for room I don’t need.
What it’s actually going to cost
Sea-Tac has some of the heaviest rental taxes and fees of any airport in the country, so the headline daily rate is sort of a lie. Here’s what to actually expect on a 5-day intermediate booking:
| Line item | About |
|---|---|
| Base rate (intermediate, Costco) | $25–$40/day × 5 |
| Concession recovery fee | ~11.1% of base |
| WA sales/use + King County stadium tax | ~10.6% of base |
| Customer Facility Charge | $6/day × 5 = $30 |
| All-in 5-day total | ~$220–$310 |
So somewhere between forty-five and sixty bucks a day, all said. Which I think is reasonable for what we’re getting.
The booking strategy I’m using
Three steps, in order:
First, I pulled a quote on costcotravel.com for SEA, May 11 (early morning) to May 16, intermediate. I noted the lowest price across the four big suppliers it shows.
Second, I cross-checked the same trip on AutoSlash, which layers coupon codes on top of base rates. Sometimes it beats Costco. You enter your Costco membership in their form so they can stack it.
Third, I booked the cheaper of the two with no prepay, so I can cancel and rebook for free if the rate drops. AutoSlash will keep tracking the price after you book — if it drops, you rebook the new lower one and cancel the old.
Skip the CDW (probably)
This is the part most people don’t realize and it’s where the real money is.
The Collision Damage Waiver — that $20–35/day add-on the counter agent will push hard — is something most major credit cards already cover for free if you pay for the rental on that card. Visa Signature, World Mastercard, and American Express all generally include rental coverage that extends to Canada, for trips under 31 days.
I’m calling my card’s benefits line before the trip to confirm coverage in Canada and verify it’s primary or secondary, but assuming it’s there: declining CDW saves around $100–$175 over five days. That’s almost the entire base rental cost.
You also want to confirm your personal auto insurance extends to rentals — most U.S. policies do, including in Canada, but call and ask. It’s a five-minute phone call that’s worth the peace of mind.
The border crossing checklist (this is the part nobody talks about)
I’ve never crossed into Canada before, and I’ve definitely never crossed into Canada in a rental with a 4-year-old in the back seat. So I made a list.
For the rental counter at Sea-Tac:
- Driver’s license
- The credit card I booked with (must be in my name)
- Costco card
For the border (both directions):
- Passports for all three adults
- A passport for my daughter if she has one — otherwise her original or certified-copy birth certificate. U.S. minors 15 and under can cross by land with just a birth certificate, though a passport is smoother
- The Canadian Non-Resident Insurance Card from the rental counter
- The rental agreement
- If your child’s other parent isn’t on the trip, a signed consent letter from them giving permission for the child to leave the country. CBSA officers genuinely do ask, especially when only one parent is present. The letter needs both parents’ names, the child’s full name and date of birth, the dates of travel, the other parent’s signature, and a phone number. Notarized is best.
We’re crossing at Peace Arch in Blaine, which is the standard Sea-Tac-to-Vancouver route. Wait times are wildly unpredictable — anywhere from 10 minutes to 90+ — so I’m checking cbp.gov/border-wait-times the morning of and aiming for mid-morning on a weekday if we can swing it.
A few practical road-trip notes
It’s about 145 miles from Sea-Tac to downtown Vancouver. Roughly 3 hours of actual driving plus the border, so plan for 4 to 4.5 hours total.
Fill up on the U.S. side before crossing. Gas in B.C. is meaningfully more expensive — like 25–40% more per gallon — and you have to return the rental with a full tank anyway, so top off again on the U.S. side on the way home.
Most U.S. cell plans include Canada now (T-Mobile and Verizon do, AT&T sometimes doesn’t), but I’m calling my carrier before the trip to make sure I don’t hand my mom a $200 roaming bill. And I’m bringing a no-foreign-transaction-fee credit card, because everywhere in Vancouver takes U.S. cards but the foreign-transaction fees on the wrong card add up fast.
You don’t need cash CAD. Every shop, gas station, and parking meter up there takes U.S. credit cards.
Why we’re doing this trip
Honestly? I got free plane tickets to Seattle. That’s the whole inciting incident. And once we had the flights, it felt silly not to make something bigger out of it — so I roped in my parents and my daughter, and we tacked on a few days in Vancouver while we’re already out there. None of us have ever been to Vancouver. My daughter’s been to Seattle once before, when she was 2, but she doesn’t remember any of it — so this is basically all four of us seeing the Pacific Northwest for the first time together. It’ll also be her first time leaving the country.
Five days isn’t a long time. But it’s the kind of trip my daughter might actually remember pieces of when she’s older, and that feels worth a little planning headache and the price of one rental car.
If you’re trying to put together a similar trip — fly into Sea-Tac, drive up, see Vancouver, come back — I hope this saves you the evening I spent figuring it out. You can find more of my travel notes here as the trip unfolds.