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Smart Export Guarantee for UK Businesses: 2026 Tariff Guide

How SEG works for commercial solar in 2026. Tariff range 4-15p/kWh. MCS certification, 5MW cap, application process, income forecasting and supplier comparison.

SEO Dons Editorial • 4 February 2026 •Updated 15 April 2026

The Smart Export Guarantee replaced the old Feed-in Tariff in January 2020 and remains the only UK-wide export support mechanism for new solar installations in 2026. It is regulated by Ofgem, paid by licenced electricity suppliers, and unlike the FIT it is market-rate rather than fixed-tariff. That makes the choice of supplier — and the structure of your tariff — a meaningful part of project ROI.

This guide is for commercial decision-makers: how SEG works for businesses specifically, what tariffs are available in 2026, eligibility, the application process, and how to forecast SEG income for your business case.

How SEG works in 2026

SEG is a regulator-mandated obligation on all licenced electricity suppliers above 150,000 customers to offer at least one tariff that pays for exported electricity from low-carbon generators below 5 MW capacity.

Key features of the 2026 framework:

Eligible technologies: Solar PV, wind, hydro, anaerobic digestion, micro-CHP up to 50 kW.
Capacity cap: 5 MW per generator (covers all but utility-scale solar farms).
MCS certification required. The installation must be certified by the Microgeneration Certification Scheme (or Solar Keymark / equivalent for non-MCS routes for >50 kW).
Tariff floor: Must be greater than zero. There is no statutory minimum beyond that — suppliers compete.
Metering: Half-hourly export metering required for time-of-use tariffs; standard export metering acceptable for flat-rate.
Contract length: Suppliers must offer at least one tariff with no fixed term, but multi-year fixed tariffs are common.

Unlike the FIT, SEG pays only for exported energy, not for total generation. There is no generation tariff. This shifts the economic calculus: self-consumption is now nearly always more valuable than export, and SEG is the secondary revenue stream rather than the headline.

For full regulatory detail see Ofgem’s SEG guidance hub.

2026 tariff landscape: who pays what

The commercial SEG market in 2026 ranges from 4p/kWh on the cheapest flat-rate tariffs to 15p/kWh peak on time-of-use offerings. Notable tariffs in market as of early 2026:

Supplier	Tariff	Type	Rate
Octopus Energy	Outgoing Fixed	Flat	8.0p/kWh
Octopus Energy	Outgoing Agile	Time-of-use (variable)	4–15p/kWh, peak ~12–15p
Tesla Energy	Tesla Energy Plan	Bundled (EV/battery customers)	up to 13.5p/kWh peak
E.ON Next	Next Export Exclusive	Flat	6.5p/kWh (existing customers only)
OVO Energy	OVO SEG	Flat	4–5p/kWh
EDF Energy	Export+	Flat	5.6p/kWh
British Gas	Export & Earn Plus	Flat	6.4p/kWh
Good Energy	Export Tariff	Flat	5.5p/kWh
Scottish Power	SmartGen Export	Flat	5.5p/kWh
Bulb (now Octopus)	Migrated to Outgoing	Flat	per current rate

Rates change. Confirm at point of application with each supplier. The tariff economics for commercial customers split into two clear modes:

Flat-rate SEG (4–8p/kWh)

Simple, no metering complexity, paid against a quarterly export reading or HH-metered export volume. Best fit for businesses without a battery, without a sophisticated EMS, and with predictable export profiles.

Time-of-use SEG (4–15p/kWh)

Pays variable export rates by half-hour, with the highest rates typically falling 16:00–19:00 weekday. Requires HH export metering (most commercial systems above 100 kW already have this). Best fit for businesses with battery storage that can export from stored energy during peak windows, or for sites with afternoon-skewed generation profiles.

For a site without battery storage, time-of-use SEG often pays slightly less than a flat-rate tariff because solar generation peaks midday and the highest rates are after peak generation has fallen. The maths flips with battery — store mid-day, export at peak.

Eligibility: what disqualifies a commercial site

The framework is broadly inclusive, but four categories of issue cause SEG applications to fail:

Missing MCS or equivalent certification. Most common reason for application rejection. The installation must be certified, not just installed by an MCS-registered installer. The certificate is issued post-commissioning.
Self-supply via private wire (not exporting through the public network). SEG only pays for energy exported through your meter to the public grid.
Capacity above 5 MW. Excluded from SEG; large generators use ROC legacy or PPA off-take arrangements.
Existing FIT recipient on the same MPAN. Can’t double-claim. Some FIT generators with deemed export (50% deemed) are better off remaining on FIT — modelling required.

Commercial sites also need to ensure the DNO has accepted the connection as exporting (G98 or G99) — see G98 vs G99 explained. A site connected as “export limited” or “no export” cannot claim SEG against unmetered exports.

The application process — step by step

Commission with MCS certification. Your installer issues the MCS certificate post-commissioning. Allow 1–2 weeks.
Confirm DNO export sign-off. G98 acknowledgment (sub-100 kW) or G99 commissioning paperwork (above 100 kW).
Choose your supplier. They do not have to be your import supplier.
Apply. Supplier-specific online or paper form. Required documents: MCS cert, DNO sign-off, MPAN, signed declaration.
Metering check. For half-hourly metered sites, the supplier confirms export metering is configured. For non-HH sites, manual quarterly readings are typical.
First payment. Quarterly arrears in most cases — first cheque/transfer 3–6 months after first export.

Total elapsed time: typically 6–10 weeks from MCS certification to first payment.

Forecasting SEG income for your business case

For a commercial system, SEG income forecasting requires three numbers:

Annual generation kWh (from PVGIS or installer modelling)
Self-consumption % (from half-hourly load modelling, or estimated from annual consumption profile)
SEG tariff (chosen supplier rate, blended for time-of-use)

Worked example for the 200 kW industrial site from our cost guide:

Annual generation: 190,000 kWh
Self-consumption: 60% = 114,000 kWh kept on site
Export: 40% = 76,000 kWh sold via SEG
Tariff: 8p/kWh (Octopus Outgoing Fixed)
Annual SEG revenue: £6,080

For a small office at 50 kW with 70% self-consumption:

Generation: 47,500 kWh
Export: 14,250 kWh
Tariff: 8p/kWh
Annual SEG revenue: £1,140

For a logistics warehouse at 800 kW on a time-of-use SEG with battery storage shifting export to peak:

Generation: 760,000 kWh
Net export with battery: 30% = 228,000 kWh
Blended tariff with peak shift: 11p/kWh
Annual SEG revenue: £25,080

These numbers make a non-trivial difference to the project IRR — typically adding 1–3 percentage points.

Maximising SEG: practical tactics for 2026

Choose a non-incumbent supplier

You are not required to take SEG from your import supplier. Octopus Outgoing pays 8p flat to anyone with an MCS-certified installation, regardless of where you buy your import electricity. Many commercial customers default to their import supplier and lose 2–3p/kWh by not switching SEG.

Get half-hourly export metering even if the headline tariff is flat

HH export metering future-proofs the site for time-of-use tariffs — switching tariff later is far easier when the metering is already in place. Cost of HH metering on a commercial site is typically negligible vs the value unlock.

Pair time-of-use SEG with battery storage

The arbitrage from charging mid-morning and exporting at peak transforms the export economics. See our battery storage analysis for the full maths.

Reread your tariff annually

SEG tariffs are typically not fixed indefinitely. Octopus, Tesla Energy and others adjust periodically. An annual SEG tariff review takes 30 minutes and can recover £500–£5,000 of missed revenue depending on system size.

Don’t accept “deemed export” without checking

Some legacy commercial setups have deemed export (e.g. 50% of generation assumed exported). For sites with high self-consumption, this overstates revenue but locks you in. For sites with high export, it understates. Ensure your contract reflects metered export.

SEG vs PPA — a fork in the road

For larger systems, the decision often becomes SEG (you own the system, sell exports at SEG tariff) vs PPA (third party owns the system, you buy generation at agreed rate, exports go to the off-taker).

Rule of thumb in 2026:

Below 250 kW: SEG nearly always wins because PPA off-takers pay a low generation rate to cover their margin.
250 kW – 1 MW: Comparison required, project-specific.
Above 1 MW: PPA frequently competitive, especially for capital-constrained operators.

See commercial solar financing options for the full PPA structure breakdown.

Common pitfalls

Applying with a non-MCS installation. Application will be rejected. For >50 kW systems, the MCS-equivalent route via certified installer is essential.
Not switching from old FIT. A FIT generator with 50% deemed export at FIT-era rates is sometimes better off than on SEG. Run the model before switching.
Assuming SEG revenue is guaranteed. It is contractual but rate changes happen. Most modelling assumes flat 5–8p/kWh nominal across project life.
Ignoring time-of-use opportunity. Even without battery, sites with east-west panel arrays generating into the afternoon can capture 1–2p/kWh of TOU uplift.

Bottom line

SEG is not a windfall — it is a meaningful but supporting revenue stream that adds 10–25% to the IRR of a commercial solar project depending on export ratio. Take it seriously, choose your supplier carefully, and revisit the tariff annually. Don’t let it become an afterthought your installer ticks off in week 8 of the project.

For a site-specific SEG income model in your project quote, request a quote. For sector-specific export profile analysis, see offices, warehouses, factories and farms.