We’ve been through the guidance closely enough now to have a fairly good sense of where applications are likely to go wrong, and it’s rarely the big, obvious things. It’s usually one of a handful of specific, avoidable errors.

The first is applying against the SIC code a business assumes it has rather than the one actually registered at Companies House. Codes drift over time, especially for businesses that have diversified since incorporation, and the eligibility test runs strictly off what’s on the public register — not off a description of what the business currently does. Checking the actual registered code, not a remembered version of it, is a five-minute task that avoids a real problem.

The second is treating the product test loosely. It’s not enough to be broadly in the right industry; the specific product has to correspond to an eligible six-digit HS code, and the evidence supporting that has to be solid enough to stand up to review. A business that assumes a close match is good enough is taking a real risk with an application it can’t revise afterwards.

The third, and probably the most common based on how often it comes up in conversation, is getting the electricity-mix calculation wrong — either through a genuine miscalculation or by including on-site generation in the figure when only grid-supplied electricity actually counts. Given the banded nature of the exemption, a mistake here doesn’t just risk rejection; it risks under-claiming an exemption a business was genuinely entitled to, simply because the mix was calculated incorrectly.

The fourth is incomplete site documentation, particularly for multi-site businesses or sites where electricity metering doesn’t cleanly separate eligible manufacturing from everything else happening on the same supply. Meter Point Administration Numbers need to be right, and the mix evidence needs to tie back to them convincingly.

And the fifth, which is less about the content of the application and more about timing, is starting to gather evidence after the window opens rather than before. Six months of billing history, site documentation, and product evidence all take time to assemble properly, and with no ability to amend a submission afterwards, rushing any part of it is a genuine risk rather than a minor inconvenience.

None of these are complicated to avoid. They just require treating the preparation phase, before October, as seriously as the application itself.