The verdict in three sentences
For an agency of 3 to 8 negotiators, a transactional SaaS at GBP 45-140/month covers CRM, sourcing and syndication with no heavy investment. A custom build at GBP 30,000-80,000 is only justified beyond 10-15 negotiators or for a network that wants a proprietary sales process and its own data. The crux isn't the software: it's the listing-to-sale conversion rate the tool lifts.
Off-the-shelf SaaS or custom: the comparison
UK agency software is mature and cheap. Custom targets networks that want to differentiate their client relationship and own their contact base.
| Criterion | Transactional SaaS | Custom build |
|---|---|---|
| Upfront cost | GBP 0 to 1,800 (setup) | GBP 30,000 to 80,000 |
| Recurring cost | GBP 45-140/month per branch | Hosting GBP 70-260/month |
| Time to launch | 1 to 3 weeks | 4 to 7 months |
| Multi-portal syndication | Included | To build/connect |
| Process customization | Low | Total |
| Data ownership | Vendor-hosted | Yours |
| E-signature | Often an add-on | Bespoke integration |
The features that sell faster
An agency saves time where information flows: from sourcing to instruction, from instruction to syndication, from viewing to signature.
| Feature | Benefit | 2026 quantified impact |
|---|---|---|
| Lead/buyer CRM | Automated follow-ups | +10-20% of callbacks kept |
| Instruction management | Sole/multi-agency tracking | Fewer forgotten instructions |
| Property sourcing | Spot listings to win | More instructions won |
| Multi-portal syndication | Enter once, all portals | 2-4 h/week saved |
| Automatic matching | Property to buyer | Faster sales |
| E-signature | Instructions signed remotely | Cycle cut by several days |
Mini case study
Karim, director of an agency in London (6 negotiators, 140 instructions/year), converted 22% of instructions to sales. Each sale earns on average GBP 6,500 in commission. By switching to a tool that automates follow-ups and property/buyer matching, he gains 3 points of conversion (25%), i.e. about 4 extra sales per year, GBP 26,000 in commission. A custom build at GBP 42,000 thus pays back in under 20 months; a SaaS at GBP 110/month (GBP 1,320/year) would in weeks if the need stays standard.
FAQ
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SaaS or custom for an independent agency?
Under 10 negotiators, a SaaS at GBP 45-140/month is almost always enough. Custom targets multi-branch networks or those wanting to own their base and process.
Is multi-portal syndication always included?
In SaaS, often yes, sometimes with a per-portal surcharge. In custom, you build or connect the feeds; expect GBP 4,000-13,000 for the main portals.
Is e-signature worth it?
Yes: signing an instruction remotely shortens the cycle by several days and avoids travel. Cost is usually flat-rate or per signature, from pennies to a few pounds per document.
How much does migrating my client file cost?
A 2026 order of magnitude is GBP 1,700 to 7,000 to import and clean an existing base, depending on volume and data quality.
Can I get my data back if I switch tools?
In SaaS, check the export terms in the contract. In custom, the data and code are yours: a key argument for a growing network.
Let's scope your project. Tell us your number of negotiators, your syndication portals and indicative budget, and we'll frame SaaS vs custom. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
