Portland’s Short-Term Rental Cap: What Buyers Should Know

Ask a buyer comparing Portland's peninsula against South Portland, Cape Elizabeth, or Yarmouth what they're weighing, and most will say price per square foot. If a rental income plan is part of the purchase, that's the wrong number to anchor on. The number that actually decides whether the plan works is buried in each town's short-term rental ordinance, and every one of these towns has written a different answer.

That difference doesn't show up on a listing sheet. It shows up mid-permit, or worse, after closing, when a buyer discovers the license they assumed would come with the property isn't available, or the ADU they planned to rent by the week comes with a countdown clock they didn't know existed.

The Cap That's Already Full

For 2026, Portland caps non-owner-occupied short-term rentals on the mainland at 293 units, a figure set by formula: 1.5 percent of the roughly 19,516 long-term rental units registered in the city the year before. That formula replaced an earlier flat cap, and the city council adopted the shift unanimously. Councilor Kate Sykes framed the goal plainly at the time: preserving Portland's long-term housing stock was the point. Councilor Roberto Rodriguez had pushed for a looser 2 percent threshold instead, and housing advocate Wes Pelletier told the council that short-term rentals were pulling stock away from the workforce, warning that working families were being pushed out of the market.

For 2026, that formula produces a number close to full. A new non-owner-occupied license in Portland is now something you wait for, not something you apply for and receive. There's a second closing door too: starting in 2026, Portland no longer accepts new registrations for tenant-occupied short-term rentals at all. Only units already registered by the end of 2025 can continue, and only through timely annual renewal.

Peaks Island runs on its own separate math entirely, with non-owner-occupied units capped at 40 annually, a detail worth knowing before assuming mainland rules travel across the harbor.

The One Path Still Open, and Its Expiration Date

One category in Portland still has no citywide cap: owner-occupied short-term rentals. If you live in the property and register it as your primary residence, with the documentation to prove it, the door stays open. That single fact reshapes what "buying for rental income" actually means in Portland right now. It's less a passive investment play and more a house-hacking one.

There's a workaround that looks like a second open door but functions more like a temporary one. Portland's code allows a newly built accessory dwelling unit to be registered as a short-term rental for a limited window tied to the unit's certificate of occupancy, roughly five years by most accounts of how the ordinance runs in practice. Once that window closes, the property has to get back in line behind everyone else waiting for a non-owner-occupied slot, the same slot that's sitting at 293 units citywide. An ADU can help an owner recover construction costs early, but it isn't a permanent short-term rental strategy on its own. It's a five-year head start, not an exemption.

The Same Question, Four Different Answers

Buyers who hit Portland's ceiling often assume the fix is simple: buy ten minutes away instead. The towns around Portland don't share its rulebook, and the differences aren't cosmetic.

South Portland's rule isn't a smaller version of Portland's cap. It's a different kind of restriction entirely. An ADU there simply cannot be a short-term rental, full stop, regardless of how many citywide licenses remain available elsewhere. Cape Elizabeth's ordinance is built around a different goal than Portland's, protecting neighborhood character rather than managing housing stock at a citywide scale, and it governs the time, place, and type of rental rather than issuing one numeric ceiling.

The Incentive That Explains the Difference

Here's the part that doesn't show up in any comparison of median prices. These towns aren't just regulating short-term rentals differently. They have different reasons to.

Yarmouth's short-term rental tax generated approximately $1.5 million in fiscal year 2023 through a 6 percent excise tax, revenue the town has used to help fund programs including wastewater infrastructure. That's the reason Yarmouth pushed its sunset clause once already, from an original November 2024 expiration to November 30, 2026, so it could keep collecting that revenue while further study continues rather than let the underlying bylaw lapse. Yarmouth's town budget has an incentive to keep renewing.

That same expiration date is now close. As of today, the current authorization runs out in about three months, and a fiscal incentive to renew is not the same as a guarantee. A buyer treating Yarmouth as the permissive option relative to Portland should ask where that renewal stands before assuming the current posture holds past this fall.

Portland's fight over its cap was never about revenue. It was about housing stock, argued in exactly those terms by the councilors and advocates who pushed the 2026 formula through. A town whose finances lean on tourism dollars from short stays has a different set of incentives than a city trying to keep units in the hands of long-term renters and owner-occupants. That difference in motive is a better predictor of where these rules head next than any single year's cap number. A buyer weighing towns on price alone is comparing outcomes without comparing the forces that produce them.

Before You Write an Offer Assuming Rental Income

1. Confirm which registration category the current use falls into: owner-occupied, non-owner-occupied, or tenant-occupied. In Portland, each faces a different 2026 rulebook, and only owner-occupied has no citywide cap.
2. If an ADU is part of the plan, ask when the certificate of occupancy was or would be issued. That date starts the clock on Portland's temporary short-term rental eligibility window for ADUs.
3. Don't assume a neighboring town is simply Portland with a higher cap. South Portland's ADU ordinance bans short-term rental use outright, regardless of any numeric limit.
4. Ask about renewal dates and sunset clauses on the underlying ordinance itself, not just the property's registration. Yarmouth's bylaw is authorized only through November 30, 2026, roughly three months from now, and renewal isn't automatic.
5. If rental income is central to the purchase, model the numbers under owner-occupied use first. It remains the one path in Portland without a citywide ceiling.

A Few Questions Worth Asking Directly

Does Portland's cap mean short-term rentals are disappearing from the city? No. It means growth has stopped for new non-owner-occupied units. Owner-occupied short-term rentals still face no citywide cap, and Peaks Island operates its own separate pool capped at 40 units.

If I'm building an ADU purely for a long-term tenant or a family member, does any of this apply to me? No. The caps and the ADU registration window only come into play if the intent is a stay under 30 days. Long-term or family-occupied use sits outside this entire framework.

Are South Portland, Cape Elizabeth, or Yarmouth simple workarounds to Portland's cap? Not automatically, and not for the same reasons. South Portland's ADU rule is a flat prohibition. Cape Elizabeth's ordinance is built around a different priority than Portland's cap. Yarmouth is currently the most permissive of the four on paper, but its authorization expires again on November 30, 2026, and depends on the town voting to renew it, not a permanent framework.

A price comparison across these towns will tell you what a property costs today. It won't tell you what you're allowed to do with it, or whether that permission is likely to last. That second question is where a rental-income purchase in Greater Portland is actually decided, and it's a question worth answering with the same care you'd give a contract review, because in practice, it is one.

If you're weighing a purchase in Portland, South Portland, Cape Elizabeth, Yarmouth, or elsewhere across the region and want to think through how a specific property's zoning and rental history actually pencils out, Adrianne Zahner brings two decades of real estate law experience to exactly these questions. Let's Connect.