Summary
The Smart Export Guarantee replaced the old Feed-in Tariff export payment when that scheme closed to new applicants in April 2019. Unlike the Feed-in Tariff, which set a fixed government-mandated export rate, SEG is a market-based mechanism — the government obliges large suppliers to offer an export tariff, but lets them compete on rate, meaning SEG tariffs vary considerably between suppliers and change over time. This is the single most important thing for tradespeople to explain to customers: there is no fixed "SEG rate" the way there was a fixed Feed-in Tariff rate, and the customer needs to shop around and switch export tariffs periodically to get a good deal, just as they might with their main electricity tariff.
The scheme applies to any small-scale low-carbon generation up to 5MW (in practice, almost always domestic solar PV, sometimes paired with battery storage, wind, hydro, or micro-CHP) exporting to the grid. For solar-only installations, MCS certification is the standard route to qualify — it's the same certification needed for Building Regulations compliance and, historically, for the Feed-in Tariff. Since this is also the qualifying certification for a range of other schemes, MCS certification has become the de facto gateway for most domestic renewable generation, and tradespeople should treat it as a default requirement for solar PV work, not an optional extra.
A common point of confusion is DIY or "plug-in" solar kits — balcony solar or small grid-tie inverters that a homeowner fits themselves. Without MCS certification (or an accepted equivalent) and a certified installer, these systems generally cannot register for SEG payments and will export for £0, regardless of how much genuinely renewable electricity they send to the grid. Tradespeople should make clear to any customer considering a self-install or budget kit that skipping certified installation forfeits SEG income entirely with almost every mainstream supplier.
Key Facts
- Smart Export Guarantee Order 2019 (SI 2019/1005) — the statutory instrument establishing the SEG obligation on large electricity suppliers
- Mandatory supplier threshold — electricity suppliers with 150,000 or more domestic customers must offer at least one SEG export tariff
- Rate-setting — suppliers can set their own SEG export rate, provided it is above zero (£0.00/kWh); there is no minimum meaningful rate mandated beyond "greater than zero"
- Eligible technologies — solar PV, wind, hydro, micro-CHP, and anaerobic digestion, generally up to 5MW capacity — domestic solar PV (with or without battery storage) is by far the most common
- MCS certification — the standard route to prove installation quality and qualify for SEG; most suppliers require it or an accepted equivalent installer certification
- Flexi-Orb — an alternative competent-person certification some suppliers accept instead of, or alongside, MCS
- Export MPAN — a unique Meter Point Administration Number for the export supply, separate from the import MPAN, set up when registering for SEG
- Smart meter / half-hourly export meter — required so the supplier can measure actual exported electricity rather than estimating it, which is how SEG payments are calculated
- No obligation to buy import electricity from the SEG supplier — a household can take their SEG export tariff from a different supplier than the one supplying their imported electricity, and many customers do so to get the best rate on each
- Battery storage and SEG — adding battery storage doesn't change SEG eligibility, but batteries change the export profile (exporting stored energy at times chosen by the homeowner rather than only when generation exceeds demand), which some suppliers reward with specific tariff structures
- Current mandatory SEG licensees — includes major suppliers such as British Gas, E.ON Next, EDF, Octopus Energy, OVO, ScottishPower, So Energy, and Utilita, though the list of obligated suppliers can change as supplier customer numbers change
- Voluntary SEG tariffs — some smaller suppliers below the 150,000-customer threshold offer SEG tariffs voluntarily to compete for solar customers, even though not legally obliged to
- DNO notification prerequisite — before SEG registration, the installation must have completed the relevant Distribution Network Operator notification (G98 for smaller systems, G99 for larger or three-phase systems)
- No SEG payment without certification for most suppliers — DIY and uncertified installations typically cannot access SEG payments through mainstream suppliers, with limited documented exceptions for competent-professional sign-off arrangements at specific suppliers
- Switching SEG tariffs — customers can and should periodically compare and switch SEG tariffs between suppliers, similar to switching a standard electricity tariff, to capture the best available export rate
- SEG is separate from the Boiler Upgrade Scheme and other heat-related grants — it applies specifically to electricity export, not to heating system upgrades
Quick Reference Table
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Try squote free →| Requirement | Detail |
|---|---|
| Governing legislation | Smart Export Guarantee Order 2019 (SI 2019/1005) |
| Mandatory supplier threshold | 150,000+ domestic customers |
| Minimum export rate | Above £0.00/kWh (suppliers set the actual level) |
| Eligible technology | Solar PV, wind, hydro, micro-CHP, anaerobic digestion, up to 5MW |
| Installer certification | MCS (standard route) or accepted equivalent (e.g. Flexi-Orb) |
| Metering | Smart meter or dedicated export meter capable of half-hourly readings |
| DNO notification | G98 (≤16A per phase, typically domestic) or G99 (larger/3-phase) before SEG registration |
| Registration document | Export MPAN, set up with chosen SEG licensee |
| Import/export supplier link | Not required — can use different suppliers for import and export |
| DIY/uncertified install | Generally ineligible for SEG with mainstream suppliers |
| Typical customer action | Compare and switch SEG tariffs periodically for best rate |
Detailed Guidance
Why the SEG rate isn't fixed
Unlike the Feed-in Tariff it replaced, SEG doesn't set a government-mandated payment level — it only mandates that large suppliers must offer some export tariff above zero. This means SEG rates vary significantly between suppliers, and even between different tariffs from the same supplier (a fixed low rate export tariff vs a variable or agile-linked tariff, for example). Tradespeople quoting solar PV installations should avoid promising a customer a specific SEG income figure without checking current rates, since these move independently of the installation itself and can change after the system is installed.
The MCS certification gateway
MCS certification does double duty for most domestic solar installations — it satisfies Building Regulations compliance requirements for the electrical and structural work, and it's the qualifying credential most suppliers require before registering an Export MPAN. Because of this, MCS certification should be treated as a non-negotiable line item on any solar PV quote, not an optional upgrade — a customer who skips it to save money on installation will very likely be unable to access SEG payments at all with the large majority of suppliers.
Setting up the export MPAN and meter
Once the installation is complete and DNO-notified (G98 or G99 as appropriate), the customer applies to their chosen SEG licensee, providing their MCS certificate (or equivalent) and proof of a smart meter or compatible export meter capable of half-hourly reads. The supplier then establishes an Export MPAN — a separate meter point reference from the property's normal import MPAN — against which exported units are recorded and paid. Delays in this process are common where a smart meter hasn't been correctly configured for export reading (some older or misconfigured smart meters don't correctly register export volumes), so it's worth advising customers to confirm their smart meter is working correctly before assuming SEG payments will start immediately.
Battery storage and export strategy
Adding battery storage to a solar PV system changes when and how much electricity is exported — instead of exporting only genuine surplus generation in real time, a battery lets the household store daytime generation and choose when to export or use it, or even to charge from cheap grid electricity overnight and export it later at a more favourable SEG rate on some tariff structures (sometimes controversially, since this isn't "self-generated" export in the way SEG was originally conceived). SEG eligibility itself isn't affected by adding a battery, but the household's overall value from the combined system depends heavily on tariff structure, time-of-use import pricing, and how the battery is controlled.
Choosing SEG suppliers independently from the main energy contract
One of the more valuable but underused pieces of advice for solar customers is that they don't have to take their SEG export tariff from the same supplier as their household electricity import. Comparing SEG rates across all mandatory and voluntary licensees — independent of who supplies the household's day-to-day electricity — often reveals a materially better export rate than simply defaulting to whichever supplier already bills the customer.
Frequently Asked Questions
Do I have to use MCS certification, or can I use another installer scheme?
MCS is the standard and most widely accepted route, but some suppliers accept equivalent competent-person certification such as Flexi-Orb, and at least one major supplier has a documented exception process using a competent-professional sign-off instead of MCS. Always check the specific supplier's SEG registration requirements before assuming an alternative certification will be accepted, since acceptance varies by supplier.
What happens if I install solar panels myself without a certified installer?
In almost all cases, a self-installed or uncertified system will not be eligible for SEG payments through mainstream suppliers, meaning any electricity exported to the grid is effectively given away for free. This is one of the strongest arguments for using a certified installer even where a DIY kit appears cheaper upfront.
Can my SEG rate change after I sign up?
Yes — most SEG tariffs are subject to change like any other energy tariff, particularly variable-rate SEG tariffs. Fixed-rate SEG tariffs lock in a rate for a set period (commonly 12 months), after which the customer needs to review and potentially switch again to maintain a competitive rate.
Does adding a battery increase my SEG income?
Not automatically — SEG pays for electricity exported to the grid, so a battery only increases SEG income if it changes the timing or volume of what's ultimately exported in a way that benefits the household under their specific tariff structure. Some households actually export less overall after adding a battery, because more of their generation is used or stored at home instead of exported, which can reduce SEG income even as it reduces the household's overall electricity bill through self-consumption savings.
Is the Smart Export Guarantee going to be replaced or scrapped?
As of September 2026, SEG remains the current mechanism for domestic export payments, governed by the Smart Export Guarantee Order 2019. There is no confirmed replacement scheme in force. Given how the Feed-in Tariff was previously replaced by SEG, tradespeople should stay alert to any future scheme changes and avoid presenting SEG as a permanently fixed feature of a solar PV investment case.
Regulations & Standards
Smart Export Guarantee Order 2019 (SI 2019/1005) — statutory basis for the SEG obligation on qualifying licensed electricity suppliers
MCS (Microgeneration Certification Scheme) — installer and product certification scheme underpinning most SEG registrations
Engineering Recommendation G98 — DNO notification process for smaller (typically domestic, ≤16A per phase) grid-connected generation, a prerequisite for SEG registration
Engineering Recommendation G99 — DNO notification/application process for larger or three-phase generation installations
Building Regulations Part P — electrical safety notification requirements applicable to solar PV installation work
BS 7671 — Requirements for Electrical Installations (IET Wiring Regulations), Section 712 covering solar PV installations
Can I Get SEG Without MCS? UK Supplier Rules 2026 - Balcony Solar Guide UK
solar pv export tariff sei — Export tariff mechanics and SEG income estimation for solar PV systems
mcs certification solar — MCS certification process and requirements specific to solar PV installations
dno g98 g99 applications — G98/G99 notification process and thresholds in detail
solar battery storage installation — Battery storage installation, MCS certification for SEG payments, chemistry and sizing considerations
solar pv system sizing — System sizing methodology affecting both self-consumption and exportable generation