Online Seller MTD + Self Assessment Tracker

Selling on Etsy, eBay, Vinted, Amazon or Depop brings its own record-keeping questions — where postage goes, how to treat the £1,000 trading allowance, and how to combine sales from several platforms into one Self Assessment. This Excel workbook is built specifically for online sellers, where generic tax spreadsheets leave you guessing.

Across eleven tabs you get:

• An Income Log with a platform dropdown and a 'Sales by platform' view, while HMRC still gets one combined turnover figure
• Expense categories tuned for selling online (stock, postage, packaging, fees, advertising, mileage), each mapped to the correct HMRC box
• A Category Glossary that spells out exactly where costs like postage and packaging go (box 18, per HMRC's Helpsheet 222)
• A Trading Allowance Check comparing actual expenses against the flat £1,000 allowance and flagging which is lower
• A cumulative Quarterly Update with a live deadline countdown, and a Year-End Summary mapped to SA103S

The maths is proven with a 46-transaction worked example across seven platforms and all four quarters, hand-calculated then independently re-checked. 126 of 126 QA checks pass, shown on the file's QA & Version tab.

This is a record-keeping tool, not tax advice and not HMRC-recognised filing software. Built for UK online sellers below the £90,000 VAT threshold, whether a £2k side hustle or a £50k+ full-time shop.