Choosing a CRM is one of the more consequential technology decisions an estate agency makes. The wrong choice costs months of migration pain and staff retraining. The right choice becomes invisible infrastructure — something your team uses without thinking about it, every day.
This guide covers the five CRMs that dominate the UK residential sales market: Alto, Reapit, Dezrez, Loop, and Rex. For each one, we've focused on what it does well, what kind of agency it suits, and what it doesn't cover out of the box — specifically around the question of inbound buyer qualification, which is where CRMs consistently leave a gap.
Disclosure: Sift is CRM-agnostic — qualified leads can be routed to any of these CRMs via CSV export (every plan), Zapier, an outbound webhook, or the REST API (Growth and Scale). Native one-click CRM integrations are on the roadmap. We've written this guide to be genuinely useful to agents evaluating their options — not as a pitch for Sift. Where Sift is relevant, we've said so clearly and positioned it as a complementary tool, not a replacement.
What an estate agent CRM does
Before comparing systems, it helps to be clear on what CRM software actually covers — because the term is used loosely, and different products cover different parts of the picture.
At the core, an estate agent CRM handles:
- Contact and applicant records — storing buyer, vendor, landlord, and tenant details
- Pipeline management — tracking instructions, viewings, offers, and sales progression
- Portal integration — syncing listings to Rightmove, Zoopla, OnTheMarket, and others
- Reporting and analytics — branch performance, conversion rates, pipeline value
- Communication logging — recording calls, emails, and notes against records
- Workflow automation — tasks, reminders, and templated follow-up sequences
What most CRMs do not cover — and this matters — is the moment before a lead enters the system. When a buyer submits an enquiry on your website at 9pm, a CRM creates a record. It doesn't have a conversation with that buyer to establish whether they have a DIP, whether they have a property to sell, or whether they're looking to move in six weeks or six months. That pre-CRM qualification layer is handled separately, which we'll return to at the end of this guide.
The five major UK estate agent CRMs
Alto is the cloud-native CRM from Houseful, the parent company of Zoopla. It's one of the most widely used systems in UK residential estate agency, particularly among mid-size independent and small chain agencies.
Its strengths lie in its portal integration (given its Zoopla parentage), its modern web-based interface, and its reasonably open API that supports third-party integrations. Alto Lead Flow is a built-in feature that helps teams manage and automate follow-up on leads already inside the CRM.
Alto suits agencies that want a capable, modern system without the overhead of an enterprise-grade deployment. The cloud-first architecture means minimal IT setup, and the Zoopla integration is tight by default.
Reapit (AgentOS) is the dominant CRM in the large agency and agency group segment. It's an enterprise-grade system with deep functionality across sales, lettings, and property management, and it's typically the choice of multi-branch or corporate agencies that need sophisticated reporting, compliance workflows, and group-level data views.
Reapit's Foundations platform is an open API ecosystem that allows third-party software — including Sift — to integrate with live Reapit data. This makes it one of the most integration-rich CRMs in the UK market. Reapit is also building out RAI, an AI assistant that operates inside the CRM to help negotiators with tasks and insights once leads are in the system.
Reapit suits larger agencies, groups, or franchises that need a battle-tested, deeply functional system and are willing to invest in proper implementation and training.
Dezrez — and its web product Rezi — is a Welsh-founded CRM with a reputation for flexibility and a REST API-first architecture. It's commonly used by independent agencies that want a capable system with reasonable customisation options and a vendor that's more responsive to smaller customers than the larger enterprise players.
Dezrez covers sales, lettings, and property management. Its REST API allows integration with third-party tools, and the system has a solid reputation among independent agencies in Wales and across England.
Dezrez suits independent and boutique agencies that want a well-featured CRM with good integration options and without the enterprise-tier pricing of Reapit.
Loop is a modern, subscription-based estate agent CRM designed for smaller and mid-size agencies. It originated in the lettings sector (as LetMC) and has expanded into sales. The system emphasises ease of use, a clean modern interface, and straightforward onboarding — making it a popular choice for agencies that have outgrown spreadsheets and basic tools but don't need enterprise-level complexity.
Loop is well-regarded for its client-facing features and responsive support. It suits agencies that want a modern, approachable CRM without the implementation overhead of larger systems.
Rex is a CRM built by Rex Software, an Australian company that entered the UK market and has grown a solid user base among sales-focused estate agencies. Rex handles sales, lettings, and property management, and it includes Rex AI Prospecting — an AI module designed to identify potential vendors and buyers for outbound targeting.
Rex is known for its clean interface, strong contact management, and the AI Prospecting feature that helps proactive agents find new business. It suits agencies that prioritise proactive outbound activity alongside standard pipeline management.
Note that Rex AI Prospecting is an outbound tool — it identifies people to contact. It doesn't cover the qualification of inbound enquiries, which is a separate function covered by tools like Sift.
Side-by-side comparison
The table below summarises the key dimensions for each system. Feature availability and pricing change — verify current details with each vendor before making a decision.
| CRM | Typical agency size | Deployment | Open API | AI features | Portal sync |
|---|---|---|---|---|---|
| Alto | Small–large | Cloud | ✓ | Lead Flow | Rightmove, Zoopla, OTM |
| Reapit | Large & groups | Cloud | ✓ Foundations | RAI (rolling out) | Rightmove, Zoopla, OTM |
| Dezrez | Independent–mid | Cloud | ✓ REST | None built-in | Rightmove, Zoopla, OTM |
| Loop | Small–mid | Cloud | Partial | None built-in | Rightmove, Zoopla, OTM |
| Rex | Small–mid | Cloud | ✓ | AI Prospecting | Rightmove, Zoopla, OTM |
How to choose
You're a large agency or group
Reapit is the dominant choice at this scale. Its Foundations platform means you can build or integrate whatever you need on top of it, and the depth of its reporting and compliance features is hard to match. The implementation and licensing cost is significant, but it reflects a system built for complex, multi-branch operations.
You're a mid-size independent agency
Alto is the most natural fit for most mid-size agencies. It's modern, cloud-native, and has a strong integration ecosystem. Its Zoopla parentage is either a feature or a consideration depending on your portal strategy. Dezrez is a credible alternative, particularly if you want a more flexible API relationship and a vendor that's more responsive to smaller customers.
You're a smaller or newer agency
Loop is worth serious consideration. It's designed to be approachable and well-supported, and it works well for agencies that want to get operational quickly without a heavyweight implementation. Rex is also competitive at this size, particularly if proactive outbound activity is central to how your team works.
Switching CRM
CRM migration is painful regardless of the systems involved. Before switching, map every data type you use (contacts, applicants, instructions, viewings, notes) and confirm the destination system can ingest it cleanly. Budget for six to eight weeks of parallel running and expect a productivity dip. The main reason agencies delay switching is the fear of this process — which is usually worse in anticipation than in execution.
The gap all five CRMs share
Every CRM on this list handles the pipeline once leads are in the system. None of them handle what happens before that — the moment a buyer submits a portal or website enquiry outside of office hours and there's no one available to have a qualifying conversation.
What CRMs don't cover
When a buyer enquires at 9pm, a CRM creates a record with a name, email, and property reference. It doesn't establish whether the buyer has a DIP, a property to sell, a solicitor instructed, or a real timeline. That data is missing until a negotiator calls — which might be 12+ hours later.
What the pre-CRM layer covers
An AI qualification layer on your website engages the buyer immediately — asking about mortgage status, chain position, and timeline before they close the tab. The qualification record lands in the Sift dashboard and — on Growth and Scale — can be routed into your CRM via Zapier, webhook or API. So by 9am the next morning your negotiators have scored leads, not a raw inbox.
This is the specific problem Sift solves. It's a website chat widget that runs a qualification conversation with every inbound buyer — 24/7, regardless of office hours — and delivers structured lead records to your dashboard and into whichever CRM you use via Zapier, webhook or API (Growth & Scale). It doesn't replace your CRM. It fills the gap before the CRM starts.
Sift is CRM-agnostic: qualified leads reach Alto, Reapit, Dezrez, Loop or Rex via Zapier, an outbound webhook, or the REST API (Growth & Scale), and CSV export on every plan. Native, one-click CRM integrations are on the roadmap.
A note on AI features within CRMs: Both Reapit (RAI) and Rex (AI Prospecting) include AI capabilities — but they operate inside the CRM and focus on different problems. Reapit RAI helps negotiators with tasks and insights on leads already in the system. Rex AI Prospecting identifies potential vendors and buyers for outbound contact. Neither covers the inbound qualification gap described above. They're complementary to Sift, not overlapping.
Summary
There is no single "best" estate agent CRM. The right choice depends on agency size, technical appetite, budget, and how much customisation you need. What's true for every agency, regardless of CRM choice, is that the CRM only works as well as the data going into it — and that data quality starts at the point of first enquiry.
If you're evaluating CRMs, get demonstrations from at least three vendors. Ask specifically about their API, their data migration process, and what integrations they support. And whatever you choose, consider how you'll handle the qualification of inbound leads before they reach it.