Mobile Phone systems for Estate Agents
THE BRANCH PHONE RINGS.
EVERYONE IS OUT ON VIEWINGS.
Applicants ring the branch, get no answer, and book a viewing with the agent down the road. Vendors ring to ask about their offer, get voicemail, and start wondering if they instructed the right firm.
ONSIM puts recorded numbers on every negotiator's mobile, natively ON-A-SIM - the branch landline, negotiators' existing business mobile numbers ported in, or both side by side. Calls to the branch ring the whole team - at a valuation, on a viewing, in the car - every outbound call shows the number you choose, and everything is recorded and managed on one system.
Answer more applicant calls, prove you called people back, and keep negotiators' personal mobiles out of the property market.
Instructions are won on the phone
Tailored Phone Solutions for Estate Agents
Key Features Built for Your Branch:
A branch phone system that follows the team out of the branch. No apps, no VoIP dropouts mid-valuation - just your branch number, on every negotiator's mobile, with a record of every call behind it.
The Branch Number, Answered Anywhere
A hunt group rings every negotiator's mobile when the branch number is called - simultaneously or in sequence. An applicant calling about a new listing gets a human at a viewing, not a voicemail at a desk.
Every Outbound Call Shows the Branch
Negotiators call applicants and vendors from their own mobiles, and the caller ID shows your branch landline. Callbacks come to the branch number, personal mobiles stay private, and departing staff don't take your applicant book with them.
Recording as Evidence, Not Admin
On-network call recording (an optional paid add-on) captures offer conversations, fee negotiations and difficult vendor calls at network level - no apps, nothing for negotiators to remember to press.
Proof You Called Back
ONSIM's real-time call logs include attempted calls - outbound calls that rang and were never answered. When an applicant claims "no one ever got back to me", you have a timestamped record that says otherwise. Most mobile networks can't show you this at all.
Out-of-Hours Handling
Route evening and weekend calls to the on-duty negotiator, an answering service or voicemail - and change the routing yourself when the rota changes. Saturday callers are often your most motivated applicants.
Search Your Calls with AI
AI Insights (an optional, opt-in add-on) transcribes recorded calls and makes them searchable - review how offers were presented, settle "who said what" internally, and coach new negotiators on real conversations.
"Did you actually pass on my offer?"
Every estate agent knows where this conversation goes. A sale falls through, a buyer misses out, and someone alleges an offer was never passed on, or that the branch never returned their calls. Under the Estate Agents Act 1979, agents have a duty to pass offers on to the seller promptly and in writing - and most agents belong to The Property Ombudsman or PRS redress schemes, where complaints routinely turn on whether a call happened and what was said on it. Without records, it is your negotiator's word against theirs.
ONSIM gives you two kinds of evidence. On-network call recording (an optional add-on) captures the conversation itself - the offer communicated to the vendor, the advice given to the applicant, the fee agreed. And ONSIM's real-time call logs include attempted calls: outbound calls that rang and were never answered. When a complainant says "no one ever called me back", most networks leave you with nothing - an unanswered outbound call never appears on a normal phone bill. On ONSIM it is timestamped in your dashboard the moment the negotiator hangs up. We've written up why other mobile networks don't log attempted calls.
To be clear: no phone system makes you compliant by itself, and nothing here is legal advice. What ONSIM does is help you evidence what your branch actually did - the offer call that was made, the callback that was attempted, the time and the number - so a dispute becomes a matter of record rather than recollection.
What our customers say.
" One of the best services I have ever received! "
Mubasher
Small business owner
" Amazing company the service is second to none! Support staff are great and have helped me so much. Really polite and helpful. "
Smith & Sullivan Ltd
Small business owner
" My name is John Morrison I have two businesses and the staff at ONSIM were brilliant.....instant replies and very polite couldn't ask for more from them. Thanks for everything "
John Morrison
Small business owner
Still have doubts?
Can you record the mobile numbers our negotiators already use?
Yes. Negotiators can port their existing business mobile numbers to ONSIM - the same process as switching networks. Applicants and vendors keep calling the number they already have, and every call and SMS on it is then recorded at network level and managed in the same dashboard as your branch numbers. Ported mobiles and branch landline identities run side by side on the same system.
How does the branch number ring negotiators who are out on viewings?
Each negotiator gets a Landline SIM (physical or eSIM) in the phone they already carry. Calls to the branch number ring the team via a hunt group - everyone at once, or in sequence - so an applicant call is answered by whoever is free, wherever they are. No app, no Wi-Fi, no divert charges: the branch number is native on each SIM.
Can negotiators call applicants without giving out their personal mobiles?
Yes - that's the point. Outbound calls from a Landline SIM display the branch landline number, so applicants and vendors save and call back the branch, not the individual. Negotiators' personal 07 numbers stay private, and when someone leaves, the relationships stay with the firm.
Can we prove we called an applicant or vendor back?
Yes. ONSIM's real-time call logs include attempted calls - outbound calls that rang unanswered - with a timestamp against the number dialled. Most mobile networks never record unanswered outbound attempts, so "you never called me back" is normally impossible to disprove. With ONSIM the record exists whether or not the call connected. Read why other networks don't log attempted calls.
How does call recording help with offers and Ombudsman complaints?
Estate agents must pass offers to the seller promptly and in writing under the Estate Agents Act 1979, and most belong to The Property Ombudsman or PRS. When a complaint alleges an offer was not communicated or advice was not given, a recording of the actual call - alongside your written confirmation - is strong contemporaneous evidence of what was said and when. ONSIM records at network level (optional paid add-on), so nothing depends on a negotiator remembering to press a button. This helps you evidence what happened; it is not legal advice and does not by itself make you compliant.
Do we have to tell people calls are recorded?
If you enable recording you are responsible for using it lawfully - in practice UK businesses typically inform callers, for example with a short announcement or a line in your terms of business. Our team can talk you through how other customers handle it, but for your specific obligations speak to your own adviser. Recording is off by default and only enabled if you opt in. See mobile call & SMS recording.
What is AI transcription and what would we use it for?
AI Insights is an optional, opt-in paid add-on that transcribes recorded calls and makes them searchable in plain English. Branch managers use it to review how an offer was presented before responding to a complaint, and to coach new negotiators using real calls instead of role-play. It only processes calls when you enable it.
What happens to our branch landline at the PSTN switch-off?
The UK's copper phone network is being switched off by January 2027, and traditional branch landlines will stop working. ONSIM is PSTN-safe: port your branch number to ONSIM and it lives on the mobile network instead - on the team's SIMs, not a box in the back office. See our PSTN switch-off guide.
Can we keep the branch number we have advertised for years?
Yes - port your existing landline number to ONSIM and keep every board, window card and portal listing exactly as it is. Porting typically completes in 10–14 working days and the port-in fee is covered.
We have multiple branches - can each keep its own local number?
Yes. Each branch keeps (or picks) its own local number - see our local numbers range covering every UK area code - with its own hunt group of negotiators, and every SIM can carry more than one number. A negotiator covering two branches can display whichever branch they are calling for.
What does it cost for a typical branch?
A Virtual Landline at £5/month + VAT forwards branch calls to one mobile - a starting point for a one-person agency. Most branches use the Landline SIM at £10/user/month + VAT with unlimited UK calls and SMS, one hunt group included on 2+ user accounts, and UK data bundles from £2. Call recording, IVRs and AI Insights are paid add-ons. Monthly rolling, cancel any time.
Flexible pricing plans
Virtual Landline
Start simple - inbound calls forwarded to your mobile
- Inbound calls forwarded to your mobile
- No SIM swap needed
- Pick new landline number or use existing
- Up to 2,500 forwarding minutes/month
- No app, no VoIP
- Cancel any time
Landline SIM
Inbound & outbound calls - your landline number on your SIM
- UNLIMITED UK Calls & SMS**
- Inbound & outbound calls show your landline number
- Standard or eSIM
- Advanced Features
- UK Data Bundles (2GB,4GB,10GB,20GB,40GB @ £2,£4,£6,£8,£10)
- Pick new landline or use existing
- Cancel any time
- Trusted by 7,500+ UK businesses
Want to speak to our sales team? Call us now on +443338804008
All prices shown are ex VAT**UK Mins are outbound calls to major (O2, Vodafone, EE and Three) UK mobiles (07), landlines (starting 01, 02, 03) and freephone numbers (0800, 0808). Unlimited call and SMS allowances are subject to our fair usage policy (5,000 mins and 1,000 SMS). Usage outside of these allowances are charged at 5p/min & 5p/sms. By default we only allow calling to inclusive numbers (excluding non-standard 07 numbers) to avoid incurring additional charges. You can request that these restrictions are removed at our sole discretion.