Real estate agency software: build vs buy in London in 2026

The verdict in three sentences

Below 8 negotiators, a vertical solution (Reapit, Alto, Rex, Dezrez) is unbeatable: live in 2 weeks, multi-portal syndication included, zero maintenance overhead. Above 12 users, or if your model breaks the mould (complex lettings, property trading, self-employed agent network), a custom build amortised over 3-5 years becomes competitive again and makes you the owner of your tool. The 2026 tipping point sits around 15,000 EUR/year in cumulated licence fees.

Vertical vs custom: what you actually buy

A vertical solution is off-the-shelf software shared across thousands of agencies. You rent access, the vendor handles updates, syndication to Rightmove, Zoopla and OnTheMarket, and compliance updates (GDPR, agency regulation). A custom build is an asset you own: workflows shaped to your process, buyer matching on your criteria, no shared data, but an upfront cost and a maintenance responsibility.

Five-year total cost of ownership (TCO)

Assumption: 12-user agency, syndication to 5 paid portals, peaking at 15 users in year 3. 2026 ballpark.

*Rightmove/Zoopla feed fees are payable either way. At 12-15 users, both scenarios converge around 150,000 EUR: custom becomes attractive as soon as headcount exceeds this threshold or your process justifies higher productivity.

Mini case study

Thomas, director of a 14-negotiator agency in London (sales + lettings), pays 150 EUR/user/month, i.e. 25,200 EUR/year in licences. Over 5 years that is 126,000 EUR before the annual 5% price rise. A custom build at 68,000 EUR with 10,000 EUR/year support comes to 118,000 EUR over 5 years. Saving: ~8,000 EUR, but above all an automated buyer-matching engine that saves 3 hours/week/negotiator, roughly 40 recovered selling hours per month across the agency.

FAQ

What does custom real estate software really cost in 2026?

Budget 40,000-90,000 EUR for a tool covering listings, multi-portal syndication and buyer matching. A focused MVP (sales only) can start at 35,000 EUR, with lettings and accounting added in later phases.

From how many negotiators does building pay off?

The 2026 tipping point is around 12-15 users, i.e. roughly 15,000-22,000 EUR/year in cumulated vertical licences. Below that, the vertical almost always wins.

Can I keep Rightmove and Zoopla syndication with a custom build?

Yes, via their feed APIs (standard property format) or an aggregator. These bridges take 3-6 weeks to build and portal fees stay identical to a vertical solution.

How long before go-live?

Budget 4-7 months for a full custom build, versus 2-4 weeks for a vertical. Migrating your existing data (listings, contacts, history) is often 20% of the project.

Who owns the data and the code?

With custom, you own the source code and host your data wherever you choose: a genuine, transferable asset, unlike a vertical subscription that stops the moment you stop paying.

Let's scope your project. Tell us your negotiator headcount, target portals and whether you cover lettings, and we will cost build vs buy over 5 years. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.