UK inflation climbed to 3.1% in August, driven by higher fuel and transport prices as retailers contend with rising operating costs.
The rollout will take the retailer's total standalone US store count to 160.
DoorDash said Costco had been among the "most-searched retailers" not previously offered on its platform.
Sales revenue for the three months to 31 July 2026 totalled 6.57bn zlotys, with both stores and online returning to double-digit growth.
