At some point every growing business gets the leased line pitch, usually delivered with the phrase “dedicated connection” and a price several multiples of the current broadband bill. The pitch is not wrong, exactly; leased lines are genuinely better in the ways claimed. The question the pitch never answers honestly is whether *your* business needs those particular betters, because for a good share of SMEs in 2026, the right answer is a cheaper combination the salesperson was not selling.
Here is the plain comparison, what each actually costs, and the simple rule for which side of the line your business sits on.
The actual difference
Business broadband (today usually FTTP, full-fibre) is shared infrastructure: excellent speeds at consumer-adjacent prices, with two structural caveats. Upload is often slower than download (asymmetric), and the service is *best efforts*: no guaranteed speed, and a fault gets fixed when it gets fixed, typically within days under business terms.
A leased line is a private, dedicated fibre circuit for your premises alone: symmetric (upload equals download, which matters more than most buyers realise), uncontended (no sharing, so the speed you buy is the speed you get, always), and above all governed by a real SLA: availability guarantees around 99.9%+ and fix times measured in hours, backed by service credits. You are not buying speed so much as buying certainty with a contract attached.
The practical differences that follow: leased lines take longer to install (weeks to a few months, since a dedicated circuit may need construction), cost more (typically several hundred pounds a month against tens for FTTP, though prices have fallen substantially as fibre has spread), and come with the fix-time guarantee that broadband simply does not offer at any politeness level.
When the leased line genuinely earns its cost
Four profiles where the answer is yes:
- Downtime priced in hundreds per hour. If the internet failing stops trading (cloud-run operations, VoIP-dependent phones, tills and bookings), the SLA is insurance priced against your downtime cost, and the arithmetic usually clears easily.
- Upload-heavy work. Sending large files daily (design, media, engineering), running off-site backups within sensible windows, or hosting anything on-premises: symmetry is the quiet killer feature, because FTTP’s upload lane is where businesses actually choke.
- Many people, one pipe. Past roughly 30 to 50 heavy cloud users, contention and upload limits start showing up as everyone’s problem; the hosted phones crackling during a big upload is the classic symptom (QoS helps; capacity cures).
- Hosted infrastructure on site or strict latency needs. Servers serving remote users, site-to-site links, or private-cloud connectivity where consistency matters as much as headline speed.
When broadband (done properly) is the right answer
Here is the part the pitch omits: for many SMEs the best-value resilient setup in 2026 is full-fibre broadband plus an automatic 4G/5G failover, professionally configured. FTTP now delivers speeds that would have required a leased line five years ago; the failover covers the availability risk for a fraction of an SLA’s price; and the whole arrangement often costs a quarter of the leased-line quote.
What it does not cover: the symmetric upload, the guaranteed fix, and the contractual accountability. A business that can tolerate “very rarely, we run on 4G for a day” saves thousands a year; a business that cannot, buys the SLA. That sentence is the entire decision, and it is why the honest answer starts with your operations rather than the price list. The failover config itself is a small networking job (dual-WAN router, tested cutover) that we build as standard in our connectivity service.
The costs, roughly and honestly
Prices vary by location (rural circuits cost more to build), but 2026 shapes for a typical Scottish business premises:
- Business FTTP: tens of pounds monthly (commonly £30 to £60) for hundreds of megabits down; installs in days to weeks.
- FTTP + managed 4G/5G failover: add roughly £15 to £40 monthly plus modest hardware; the resilient-broadband package most SMEs should price first.
- Leased line: commonly £150 to £400+ monthly for 100Mb to 1Gb symmetric depending on location, on 3-year terms, installing in 30 to 90 days (occasionally longer where construction is needed, and note “excess construction charges” in quotes, which is where rural surprises live).
Two buying notes. First, lead time is a project constraint: if a leased line is right, order it against your office-move or growth timeline, not the week you need it. Second, a leased line without a failover is still one cable through one duct; critical operations pair the leased line *with* a diverse backup, because the SLA compensates for downtime but does not abolish it.
Frequently asked questions
What is the main difference between a leased line and broadband?
A leased line is a dedicated, symmetric circuit with guaranteed speeds and contractual fix times; broadband is shared, usually asymmetric, best-efforts service. You pay the difference for certainty, upload capacity and accountability.
How much faster is a leased line than fibre broadband?
Often it is not faster downstream at all: modern FTTP headline speeds compete well. The leased line wins on upload (symmetric), consistency (uncontended) and repair guarantees, which is where the value genuinely sits.
Is a leased line worth it for a small business?
If hourly downtime costs serious money, uploads constrain your work, or you host services on site: usually yes. If your operations could ride a rare day on 4G failover: usually no, and FTTP-plus-failover is the better spend. Price your downtime first; the answer follows.
How long does a leased line take to install?
Commonly 30 to 90 days from order, longer where new construction is required. Plan it into moves and projects; it is the least compressible lead time in business IT.
Can we make ordinary broadband more reliable instead?
Substantially: automatic 4G/5G failover, business-grade routing and monitoring convert good FTTP into a resilient service for modest cost. What it cannot add is symmetric upload or a contractual fix time; those remain leased-line territory.
Do we need a leased line for VoIP phones?
Usually not: calls need modest, stable bandwidth, and well-configured FTTP with QoS carries SME call volumes happily. Larger teams, heavy uploads sharing the pipe, or zero-tolerance phone operations push toward the dedicated circuit.
Price your hour, then price the line
The decision compresses to one comparison: your cost per hour of internet downtime against the monthly gap between the two options. Our free IT health check works that number out with you, tests what your current line actually delivers, and specifies either the failover build or the leased-line order, whichever the arithmetic supports. Get in touch before you sign a three-year term either way.
