Compare telecoms and VoIP quotes in London
London has some of the densest full-fibre coverage in the UK, which means connectivity is rarely the limiting factor - but the market is saturated with providers, and price is not the only variable that matters. Contract terms, porting reliability, and support quality vary considerably between providers pitching to the same London business. RFXapp collects their bids and standardises them so you can compare what they actually include.
If you are looking for the best providers in London, the most reliable shortlist is one built around your own requirements and tested with a structured brief - not a generic ranked list. RFXapp helps you find and collect quotes from the right suppliers, and analyse them so you can compare what they actually offer, not just the headline price.
What to consider before you go to market
Getting comparable quotes starts with a well-scoped brief. These are the things most businesses overlook until they're already in the process.
Hosted VoIP vs SIP trunking vs on-premise
These three architectures have different cost profiles, reliability characteristics, and administrative overhead. Hosted VoIP - where the provider owns and maintains the hardware and software - is the right choice for most London SMEs. SIP trunks suit businesses that already have a PBX they want to retain. On-premise is rarely the right choice for a new deployment unless there is a specific security or connectivity requirement. Know which model you are buying before you brief providers, or you will receive quotes that are impossible to compare.
Broadband dependency and line quality
Hosted VoIP runs over your internet connection, and call quality is only as good as your broadband. London's full-fibre coverage is strong in most central and inner-London postcodes, but some EC and WC buildings still run off FTTC connections that introduce latency and jitter under load. A provider who quotes without assessing your current broadband speed, latency, and jitter is either cutting corners or selling indiscriminately. Before going to market, run a line quality test and share the results - any reputable provider will ask for this before quoting.
Number porting: timeline and risk
Porting your existing telephone numbers from one provider to another is the highest-risk operational step in a VoIP migration. Ports can fail, delay, or complete partially - some numbers porting while others do not. The timeline is two to four weeks for a straightforward port, longer for complex multi-site or DDI arrangements common in larger London firms. During porting, calls to your number may be disrupted. Ask every provider to describe exactly how they manage ports and what their track record is for London-based migrations.
Contract length and early termination charges
Telecoms contracts routinely run 24 to 36 months, with early termination charges calculated as the remaining monthly fees. On an £800/month contract with 24 months remaining, the ETCs are £19,200. Providers rarely draw attention to this until you want to leave. Read the ETC clause carefully and calculate the maximum liability before signing - this is especially important in London where businesses move offices, merge, or change headcount more frequently than the average contract assumes.
Out-of-hours support and SLA credits
A VoIP failure outside business hours can mean phones are down when staff arrive the next morning with no way to call for help. Ask every provider for their out-of-hours support process specifically - who you call, what the response time commitment is, and what SLA credits apply if they miss it. The difference between "24/7 support" and "24/7 emergency line with a four-hour response" is significant in practice, and London-based providers cover a wide range on this.
Integration with existing tools
Most London businesses use at least one of: Microsoft Teams, a CRM (Salesforce, HubSpot), or a helpdesk platform. VoIP systems that integrate natively with your existing tools reduce friction and improve call logging. Ask every provider to confirm which integrations are included in the standard package versus available as paid add-ons - the gap between the two is often where the real cost difference sits between otherwise similar-looking quotes.
Contract traps that catch London businesses out
These are the clauses and assumptions that make two telecoms quotes look comparable on paper but several thousand pounds apart once you're locked in.
Early termination charges on 24-36 month contracts
Telecoms ETCs are one of the highest-value contract traps in SME procurement. A London business that commits to a 36-month contract at £700/month and wants to leave at month 18 faces ETCs of £12,600 - often discovered only when the business moves premises, changes structure, or finds a significantly better deal. Many businesses sign without reading this clause carefully, then either pay the exit fee or stay with a provider they are unhappy with. Before signing any telecoms contract, calculate the maximum ETC liability across the full term and decide whether you are comfortable with that exposure.
Number porting failures causing business disruption
A failed or delayed number port can mean your main London business number is unreachable for days. This is not a theoretical risk - partial port failures and delays are common in the UK market, and the consequences for inbound-dependent businesses (professional services, client-facing firms, any business where the phone number appears on marketing materials) can be severe. Porting failures tend to happen at the point of maximum operational inconvenience: the morning your old provider disconnects and the new one has not completed the port. Ask every provider about their porting process, SLA, and what compensation applies if a port fails.
"Unlimited calls" with fair use policies that cap peak usage
Unlimited call packages in telecoms almost always have a fair use policy that defines what "unlimited" actually means. Common restrictions include limits on calls to certain number ranges (0845, 0870, international), limits on concurrent calls, and restrictions on call-centre-style usage. Two "unlimited" packages at similar prices can cover very different actual usage patterns. Read the fair use policy before comparing prices - for a London office making a high volume of outbound calls, this clause can turn an apparently competitive quote into an expensive one.
Questions that separate good providers from great ones
Asking is only half the job. Below each question is what a good answer sounds like, and what should give you pause. Questions marked * are mainly relevant for larger or more complex deployments.
Good answer: A specific description of the porting process: how they submit the port request, how they communicate progress, what the typical London DDI timeline is, and a clear explanation of what they do if a port fails or is delayed - including any compensation or alternative number arrangements they put in place.
Red flag: "Porting is normally fine, we haven't had any problems." Every provider in the market has had porting problems - this answer means they either have no process for handling failures or they are not being candid.
Good answer: A specific figure at each milestone, calculated clearly. A good provider will also explain whether there are any contractual mechanisms that reduce the ETC - for instance, whether a new-premises move triggers different terms.
Red flag: Vagueness about the calculation method, or a redirect to "we can look at that if it comes up." That means they know the number is uncomfortable and are hoping you do not calculate it before signing.
Good answer: A specific phone number for out-of-hours emergencies, a named team or on-call rota, a response time commitment in writing, and an explanation of what SLA credits apply if the response time is missed.
Red flag: "You'd raise a ticket through the portal." A ticketing system is not out-of-hours support for a business with no working phones. Also watch for "24/7 support" that turns out to mean monitoring only, with no human response outside business hours.
Good answer: A specific bandwidth recommendation based on your headcount and call concurrency assumptions, a willingness to run or review a line quality test before finalising the quote, and an honest answer about what happens if your current broadband does not meet the threshold.
Red flag: "Your current broadband should be fine." This means they have not checked and are assuming the sale rather than qualifying it. Any reputable provider will want to know your current setup before committing to call quality.
Good answer: A clear, written breakdown of what is in the base package and what is charged separately - with specific reference to the integrations you use. A trustworthy provider will confirm this in the quote document, not just verbally.
Red flag: "Most integrations are included" without specifics. That hedge means some are not, and you will find out which ones when the bill arrives.
Good answer: A specific description of the fair use policy: which number ranges are excluded, what the concurrent call limit is, and what happens if usage exceeds the fair use threshold - whether that is a surcharge, a tier change, or a conversation about a different package.
Red flag: "We don't have any meaningful restrictions" without providing the actual policy document. Ask for the policy in writing before signing - every unlimited package has restrictions, and a provider who claims otherwise is either uninformed or being evasive.
Where you have more negotiating room than you think
Telecoms providers have more flexibility on price and terms than they show in their initial quote. These are the levers that work once you have competing quotes in front of you.
Multi-year commitment in exchange for a rate reduction
Providers will discount meaningfully for a 36-month versus 24-month commitment because the incremental revenue on a longer contract is high-margin for them. The trade-off is increased ETC liability. Before taking this deal, calculate the maximum ETC at the worst-case exit point and decide whether the saving is worth that exposure. If the provider will agree a capped ETC figure rather than a remaining-term calculation, the trade-off becomes considerably more attractive.
Bundle voice, broadband and mobile with one provider
Telecoms providers that cover all three - voice, broadband, and mobile - will discount a bundled contract more than three separate ones because the consolidated spend improves their account economics. This lever only works if you are genuinely willing to move all three. Using it as a bluff on one category tends to be visible. The strongest position is a genuine brief that includes all three services and competing quotes from providers who cover the full scope.
End-of-quarter timing
Telecoms providers are target-driven businesses and Q-end produces better discounts than mid-quarter. UK telecoms quarters typically close in March, June, September, and December. If your procurement timeline is flexible, building in Q-end timing - and making clear you are comparing three providers simultaneously - creates genuine urgency. This is most effective when the deal is above £500/month, where the rep has meaningful discretion.
Competitive quotes shared with the incumbent
If you have an existing provider, sharing competing quotes from two or three alternatives is one of the most reliable price levers available. Incumbents will typically match or improve on a competing quote rather than lose the account. The key is having quotes that are genuinely comparable - same service scope, same contract length - so the incumbent cannot argue the comparison is unfair.
Negotiate the ETC cap before signing
Some providers will agree a capped exit fee rather than a full remaining-term calculation - for instance, capping ETCs at six months of fees regardless of when in the contract you exit. This is a legitimate negotiating point and some London providers will accept it, particularly on contracts above £600/month. Ask for it before you sign, not after - once the contract is executed, the clause is fixed.
Pre-agree the day rate for out-of-scope configuration work
Any VoIP migration involves configuration tasks that turn out to be more complex than the initial scope assumed: additional call flows, custom IVR menus, integration setup that requires back-and-forth with your CRM vendor. Without a pre-agreed day rate for this work, each task gets priced at the moment of maximum inconvenience. Agree a named day rate for professional services work in the contract and apply it to any variation that arises during or after the migration.
From "we need a new phone system" to deal done
Describe what you need
Write your requirements in your own words - scope, location, timeline, any constraints. RFXapp turns it into a structured brief and prompts you for anything that will help providers quote accurately.
Invite your providers
Add the providers you've already shortlisted, or let RFXapp find local options. They reply by normal email - no portal, no registration.
Compare quotes side by side
RFXapp reads every response and standardises the quotes into a side-by-side view - inclusions, exclusions, assumptions and all.
Negotiate and appoint
RFXapp drafts targeted negotiation emails based on the gaps between quotes. You review and send. Then award the contract from your dashboard.
Other things London businesses source on RFXapp
Most of our users run 5-10 separate buying projects a year. This is often how they find us, but it's rarely the last thing they use us for.