Your import and export contracts are separate
When you have solar panels, you have two relationships with energy suppliers: one for the electricity you import from the grid (your normal electricity tariff), and one for the electricity you export to the grid (your SEG contract). These are separate contracts and can be held with different suppliers.
Switching your import supplier does not automatically affect your SEG contract. Your export payments will continue with your existing SEG provider even after you switch your import tariff — unless you actively choose to change your SEG provider at the same time or separately.
Switching your import tariff
Switching your import tariff works exactly the same way as for any household. Compare tariffs on a comparison site, initiate the switch with the new supplier, and your old supplier will confirm the switch date. Your smart meter readings are transferred automatically.
The main consideration for solar owners is to look for import tariffs compatible with time-of-use optimisation if you have or are planning a battery or EV. Tariffs like Octopus Go (cheap overnight rate) can significantly improve the economics of battery storage. A flat-rate tariff is simpler but misses this opportunity.
Check whether your new supplier supports the smart meter export readings correctly. Most major suppliers do, but if your export meter has not been working correctly with your current supplier, a switch is a good opportunity to ensure the new supplier sets it up properly from the start.
Switching your SEG contract
You are not obliged to keep your SEG contract with your current provider. You can switch SEG providers independently of your import tariff. SEG rates vary significantly between providers and change over time — rates between 3p/kWh and 15p/kWh are typical, so the difference on an annual basis can be meaningful.
To switch SEG provider, apply to the new provider directly. They will ask for your MCS certificate number, your export meter details, and sometimes a recent meter reading. There is no exit fee for leaving a SEG contract — they are not fixed-term in the same way as import tariffs.
Note that only suppliers with 150,000 or more domestic customers are obliged to offer a SEG tariff — these are called mandatory SEG licensees. Smaller suppliers may offer SEG voluntarily. If your current small supplier does not offer a competitive rate, switching SEG provider to a mandatory licensee is straightforward.
Practical checklist before switching
Before switching import supplier: note your current SEG provider and rate; check whether your new import supplier also offers SEG (you may be able to consolidate); confirm your smart meter will be compatible (SMETS2 meters work across all suppliers; older SMETS1 meters may temporarily lose smart functionality).
Before switching SEG provider: check current SEG rates on Ofgem's published comparison tables or individual supplier websites; confirm your export meter is registering correctly; have your MCS certificate number to hand.
After switching: monitor your first bill from the new import supplier to confirm readings are correct; monitor your first SEG payment from the new export provider to confirm export readings are being received; compare against your inverter monitoring data for the same period.