If you've kept your own Excel or Google Sheets for years, you don't have to move to full accounting software. Bridging tools submit your numbers for you.
Bridging software is the cheapest, least disruptive MTD route: you keep your spreadsheet, the bridging tool reads the totals and submits them to HMRC. Prices start from free (My Tax Digital, VitalTax free tier) to £12–£36 per year.
3 providers match this situation. Free options first.
Free bridging from Excel / Google Sheets.
My Tax Digital offers a free bridging mode that imports figures directly from spreadsheets and submits to HMRC. Also has a free accounting mode for simple digital records.
Excel add-in bridging — free tier available.
VitalTax is an Excel add-in that submits directly from your spreadsheet. Free tier for very small traders, paid tiers very cheap.
Cheap bridging software for spreadsheet users.
123 Sheets is a low-cost bridging tool — keep your records in Excel, it handles the HMRC submission. No bells, no whistles, just cheap compliance.