Vacation rental startup Stay Alfred has raised its first round of capital – a sizeable $15 million – in a bid to expand the company outside of the US.

The company confirmed the Series A round but has declined to give the identity of the Seattle-based private equity group that has invested.

Stay Alfred is actually six years old and has grown at a modest rate, with just 350 properties in the US so far.

The funding will be used to accerelate the growth of the business, with its stated ambition to pick up more than 4,000 properties around the world within the next two years.

It tries to position itself as an “urban vacation rental company” (and claims to to be the first in the US) – shorthand for downtown apartments with amenities included and servicing from the Stay Alfred team (similar to the OneFineStay model created in Europe).

US cities include Washington DC, Seattle, New Orleans, Memphis, Dallas and Boston.

CEO and founder Jordan Allen has also amassed a 72-strong team, following a career in the US military.