Portland, ME ZIP codes and sales tax by ZIP
Quick answer
These 5 ZIP codes serve Portland inside Cumberland County, and each carries the same 5.5% combined sales tax rate. ZIP boundaries are postal delivery routes, not tax boundaries — a ZIP that crosses a city or district line can contain more than one rate, so destination-based sellers should validate by full street address rather than ZIP alone.
ZIP codes in Portland
All within Cumberland County, Maine.
Why ZIP-based rate lookup is unreliable
The USPS creates ZIP codes to route mail efficiently, and it redraws them when carrier routes change. Tax jurisdictions follow municipal annexations, county lines and voter-approved district boundaries instead. In Maine, even without local add-ons, the safest practice for remote sellers is to validate the full delivery address against the Maine Revenue Services lookup at the time of sale.