Who owns OnTheMarket?
OnTheMarket is owned by CoStar (the United States, NASDAQ: CSGP), which has owned the brand since 2023.[1]
Evidence: CoStar Group, Inc. Annual Report on Form 10-K filed 2026-02-26, SEC EDGAR, 26 February 2026. Verified from filings; last checked .
Key facts
- Current owner
- CoStar Group, Inc. verified
- Owned since
- Owner HQ
- 🇺🇸 United States, Arlington
- Origin
- 🇬🇧 United Kingdom
- Category
- Internet & digital › Online commerce › Property listings
- Parent ticker
- NASDAQ: CSGP
- Last verified
- · 1 sources
About OnTheMarket
OnTheMarket is the operator of onthemarket.com, a United Kingdom residential property portal that CoStar bought in December 2023. It is held through OnTheMarket LTD, a subsidiary listed in CoStar's subsidiary exhibit, and sits in the residential segment, giving the group a presence in the UK property market beside its Australian site Domain. The 10-K gives no listing count, agent count or founding date for it, so none is stated here.
What CoStar's annual report says about OnTheMarket
Sentences about OnTheMarket from CoStar's latest annual filing[1], copied word for word.
Domain and OnTheMarket are our leading marketplaces in Australia and the U.K., respectively allowing real estate agents to advertise their listings.
Ownership timeline of OnTheMarket
Where OnTheMarket sits in CoStar
Controlling ownership as of . Brands grouped under the entity that owns them; large groups are collapsed.
Open the full CoStar ownership tree →
See the full CoStar brand portfolio (6) →
Other brands owned by CoStar
CoStar controls 6 brands on Brandtree, 6 of them in internet & digital.
Also in internet & digital
Other brands in property listings, and who owns them
CoStar has more brands in property listings on Brandtree than any other owner: 6 of 19.
| Brand | Owner | Owner based in |
|---|---|---|
| Flatmates.com.au | REA Group | 🇦🇺 Australia |
| StreetEasy | Zillow | 🇺🇸 United States |
| Flatfox | SMG Swiss Marketplace Group | 🇨🇭 Switzerland |
| Bina.az | Kaspi.kz | 🇰🇿 Kazakhstan |
| Mercado Libre Classifieds | MercadoLibre | 🇺🇾 Uruguay |
| realtor.com | News Corp | 🇺🇸 United States |
| OneRoof | NZME | 🇳🇿 New Zealand |
| Property.com.au | REA Group | 🇦🇺 Australia |
About the owner: CoStar
CoStar is a publicly listed company headquartered in Arlington, United States. Brandtree records 6 brands under its control, and it is listed as NASDAQ: CSGP.
CoStar Group is an American commercial and residential real estate information and marketplace company, incorporated in Delaware and based at 1201 Wilson Boulevard, Arlington, Virginia, with its shares on the Nasdaq Global Select Market. Its core business is the subscription CoStar database, but its 10-K for 2025 groups its portals into a commercial segment (LoopNet and others) and a residential segment (Apartments.com, Homes.com, Land.com, Domain and OnTheMarket). It bought OnTheMarket in December 2023 and Domain in August 2025, and also owns Matterport, Visual Lease, BizBuySell and Ten-X.
🇬🇧 OnTheMarket and other British brands
Brandtree records a controlling owner for 543 brands that began in the United Kingdom. 282 of them (52%) are now controlled by a company headquartered in another country, OnTheMarket among them.
Frequently asked questions
Who is the parent company of OnTheMarket?
The parent company of OnTheMarket is CoStar, a publicly listed company headquartered in the United States.
Is OnTheMarket British or American?
OnTheMarket originated in the United Kingdom, but it is owned today by CoStar, which is headquartered in the United States. So OnTheMarket is a British-origin brand under American ownership.
Since when has CoStar owned OnTheMarket?
CoStar has owned OnTheMarket since 2023.
Is OnTheMarket still owned by CoStar?
Yes. As of 9 October 2026, OnTheMarket is still owned by CoStar. The ownership record was last checked against primary sources on that date.
Sources (1) & corrections
Last verified . Every ownership fact above is backed by one of these primary documents. Numbers in brackets in the text refer to this list.
- [1] CoStar Group, Inc. Annual Report on Form 10-K filed 2026-02-26 — SEC EDGAR, SEC Form 10-K, published 26 February 2026; retrieved 2 October 2026.
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