https://tradeyoke.net/blog/tag/solar MCS, DNO applications, commissioning and handover packs. en-gb https://tradeyoke.net/blog/mcs-certificate-explained-for-installers https://tradeyoke.net/blog/mcs-certificate-explained-for-installers Sun, 31 May 2026 11:15:11 GMT The MCS certificate is what proves a solar install was done to the scheme's standards, and it is what unlocks the Smart Export Guarantee for your customer. Here is what it is, what MCS needs from you, and what goes in the handover pack. ⚠️ Solar installer is a pilot trade in TradeYoke. The documents described here are in use by pilot businesses; pilot trades are priced with those businesses rather than from the pricing page. ### The handover pack The handover pack is what the customer keeps, shows their supplier, and hands to the buyer when the house is sold. A thin pack costs you phone calls for years. A full one costs you twenty minutes. ### What belongs in the handover pack - ✓ MCS certificate — The scheme certificate for the installation. - ✓ Commissioning certificate — System tests and readings on the day it went live. - ✓ DNO paperwork — The G98 notification or the G99 approval, whichever applied. - ✓ Electrical certificate — The EIC or Minor Works certificate for the electrical work, to BS 7671. - ✓ Performance estimate — The annual generation estimate from the MCS method, with the assumptions. - ✓ Single-line diagram and layout — So the next engineer can see what was installed and where. - ✓ Warranties and manuals — Panels, inverter, battery, mounting, and the workmanship warranty. - ✓ Building control notification — Where the work was notifiable under Part P. The pilot produces the customer handover pack from the job, pulling in the certificate, the commissioning record, the single-line diagram and the DNO application, and emails it from the record so the send is on file. The DNO side, and the difference between notifying and applying, is covered in G98 vs G99: DNO applications without the wait. The electrical certificate follows the same rules as any other electrical work; the EICR post explains how certificates with an expiry become future work. > The handover pack is the last thing the customer sees from you and the first thing they show everyone else. — TradeYoke ### Where the certificate lives afterwards Filing matters more for solar than for most trades, because the documents outlive the phone they were made on. A certificate filed in the document library against the customer and the job is there when the customer moves house, when the inverter fails in year eight, and when the supplier changes its SEG rules. Search inside PDFs finds it by the inverter serial number, which is usually what the customer has to hand. Plans on the pricing page are per business. Solar firms that also do the electrical work run both trades on one account, which is what the two-trades post is about. See also: the full Paperwork & compliance guide ### Questions people ask **Can a customer get the Smart Export Guarantee without an MCS certificate?** Suppliers must offer SEG to installations with an MCS certificate or an equivalent they recognise. In practice most suppliers ask for MCS, so an install by a non-certified installer usually cannot claim it. Check the individual supplier's terms. **Does MCS cover batteries as well as panels?** Yes. MCS publishes a standard for electrical energy storage, and battery installers can be certified against it. Note that SEG pays for electricity generated and exported; a battery on its own does not qualify, and export from a battery charged from the grid is treated differently by suppliers. **Is the 0% VAT rate on solar tied to MCS?** No. The VAT relief on energy-saving materials installed in residential property is a tax rule with its own conditions, not an MCS requirement. Confirm how it applies to a specific job with your accountant or HMRC's guidance. **How long should the customer keep the certificate?** For the life of the system. It is needed for SEG, for warranty claims, for some finance and insurance products, and for the buyer when the property is sold. That is why a filed copy on your side is worth keeping too. ### Issue the certificate and the pack from the job TradeYoke's solar installer pilot produces the MCS data sheet, commissioning certificate and handover pack from the job and files them with the customer. Start a 30-day trial of Essentials with no card. [Start your free trial](https://app.tradeyoke.net/signup) ]]> TradeYoke team Solar Compliance https://tradeyoke.net/blog/g98-vs-g99-dno-applications https://tradeyoke.net/blog/g98-vs-g99-dno-applications Tue, 26 May 2026 13:15:11 GMT G98 means install then notify the DNO within 28 days. G99 means apply and get approval before you commission. Here is the threshold, the paperwork, and how to stop the wait stalling the job. 💡 Send the G98 notification from the commissioning visit, not from the office a fortnight later. It takes ten minutes while the inverter serial number is in front of you, and it is the document the SEG application will ask for. ### G99: apply first, then wait Above the threshold the DNO has to assess whether the network can take the export before anything is connected. That means an application with a single-line diagram, a site plan, the inverter's type-test evidence, the proposed capacity and the export arrangement. The DNO responds with an approval, sometimes with conditions such as an export limit, or with a connection offer if network work is needed. How long it takes depends on the DNO and the size of the job. A straightforward domestic G99 application is usually answered within the DNO's published timescale, often up to 45 working days; anything needing a network study takes longer. Your DNO publishes its own timescales, and they are the ones to plan against. > ⚠️ Do not commission a G99 system before the approval is in writing. Energising a generator the DNO has not approved can put the customer's connection agreement, and your relationship with the DNO, at risk. ### The wait that stalls the job, and how to shorten it The wait itself is not the problem. The problem is starting it too late: surveying in March, quoting in April, applying in June and then putting the install on hold. Three habits keep the job moving. Apply the day the survey confirms the size. Whether the customer has signed yet or not, an application costs little and the clock starts. Use type-tested inverters. Equipment on the ENA's type-test register needs no separate compliance evidence, which is the most common reason an application bounces. Design to the threshold when it is honest to. Where the customer's use fits a 3.68 kW export, a G98 design with export limitation avoids the wait entirely. Where it does not, say so and apply. ### Tracking the application on the job The application is a task with a status, a date and a document, and it belongs on the job, not in someone's inbox. The Solar installer trade in TradeYoke is in pilot with real installers and treats it that way: a G98 or G99 connection assessment on the job, DNO contacts by region so the right operator is a click away, the type-test documents and single-line diagram attached, and a boundary map of the site. The solar installer page covers the pilot. When the approval arrives it is filed with the job, and it goes into the handover pack described in the MCS certificate post. The customer sees the status without ringing, which is most of what they wanted. [Image: The jobs list filtered to one trade: every solar job in one place, with its priority, place and date — and the DNO application tracked on the job record.] ### The G99 application pack - ✓ Single-line diagram — Generator, inverter, protection, isolation and the point of connection. - ✓ Site plan and boundary — Where the equipment sits and where the supply enters. - ✓ Inverter type-test evidence — The ENA register reference, or full compliance evidence if not registered. - ✓ Capacity and export arrangement — kW output, phases, and any export limitation scheme. - ✓ Customer and MPAN details — The supply number from the electricity bill. - ✓ Installer details — Including who to contact with questions. Jobs that wait on paperwork are also jobs that wait to be paid. A deposit at booking and a pay link on commissioning, as described in how tradespeople get paid the same day, keep the cash moving while the DNO does its work. Pay links are part of the Premium plan and the customer portal is part of Ultimate on the pricing page; pilot trades are priced with the pilot businesses. Installers who also do the electrical certification will find the electrician page useful too. ### Questions people ask **Can I commission a G99 system before the approval comes back?** No. G99 requires the DNO's agreement before the generator is connected. If the customer needs the system live sooner, the honest options are a G98-sized design with export limitation or a conversation with the DNO about timescales, not an early switch-on. **Does adding a battery change the application?** Often. A battery with its own inverter adds generating capacity in the DNO's terms, and the total on the premises is what counts against the 16 A per phase limit. A hybrid inverter can keep the total within G98; a separate battery inverter may not. Work it out at design time. **How do I find out which DNO covers a site?** The Energy Networks Association runs a postcode lookup for the network operator, and the customer's electricity bill shows the MPAN, whose distributor ID identifies the DNO. Regional DNO contacts are stored in the TradeYoke solar pilot so the right one is on the job. **What if I forgot to send a G98 notification?** Send it now. The DNO would rather have a late notification than none, and the customer's Smart Export Guarantee application will need the paperwork. Then move the notification into the commissioning visit so it cannot be forgotten again. ### Keep the DNO application on the job, not in an inbox TradeYoke's solar installer pilot tracks G98 and G99 applications with the diagram, the type-test evidence and the DNO contact on every job. Start a 30-day trial of Essentials with no card. [Start your free trial](https://app.tradeyoke.net/signup) ]]> TradeYoke team Solar Compliance