123 Sheets Alternative for MTD Landlords: LandlordTaxAi vs 123 Sheets 2026

123 Sheets vs LandlordTaxAi — TL;DR

Prices correct as at 19 April 2026. HMRC recognition status sourced from HMRC's compatible software list.

Pricing comparison

123 Sheets positions itself explicitly as the lowest-cost HMRC-recognised bridging option, with individual landlord plans starting at approximately £10/month. The simplicity of the product keeps the price low: it does nothing other than act as the connection between your spreadsheet and HMRC's API.

LandlordTaxAi pricing is published on the LandlordTaxAi website. The monthly cost is higher than 123 Sheets' entry level, but it replaces what 123 Sheets and your spreadsheet together accomplish — plus adds AI categorisation, in-year tax estimates, and a structured quarterly review workflow. For landlords whose time has a real cost, the difference in manual effort often justifies the difference in subscription fee.

One practical consideration: 123 Sheets requires you to maintain an accurate spreadsheet throughout the year. That spreadsheet is not free — it costs your time every time you enter a transaction, reconcile a month, or correct a categorisation error. LandlordTaxAi absorbs that work into the AI layer.

Feature comparison: 12 criteria

The table below compares both tools across the twelve features that landlords most commonly ask about when choosing MTD software.

Where 123 Sheets has the advantage

123 Sheets is not the right choice for every landlord, but it is the right choice for a specific and significant group. Here is where it genuinely wins.

• 1. HMRC recognition is confirmed

  123 Sheets appears on HMRC's published list of compatible software as a bridging tool for MTD for Income Tax. For landlords who need the reassurance of an officially listed product from day one — particularly those mandated from 6 April 2026 — this matters. LandlordTaxAi's sandbox-verified, with direct submission launching soon. We are cannot currently offer the same assurance.

• 2. Full spreadsheet flexibility

  Some landlords have maintained meticulous spreadsheet records for a decade or more. Their spreadsheets contain property histories, comparison years, and custom formulas no piece of software can replicate. 123 Sheets respects that: your spreadsheet stays exactly as you designed it, and 123 Sheets only handles the submission step. LandlordTaxAi asks you to work within its own structure, which is a genuine trade-off for those with complex or idiosyncratic records.

• 3. Lowest monthly cost for HMRC-recognised compliance

  At approximately £10/month, 123 Sheets is among the cheapest ways to achieve HMRC-recognised MTD compliance. For landlords with very simple finances — one property, minimal transactions, a solid spreadsheet habit — the additional features of more expensive tools offer little extra value. 123 Sheets gets the job done at the lowest cost.

Where LandlordTaxAi has the advantage

For landlords who find maintaining a spreadsheet burdensome — or who simply want the quarterly process to take minutes rather than hours — LandlordTaxAi offers several meaningful advantages over 123 Sheets.

• 1. AI categorisation against SA105 boxes

  LandlordTaxAi reads your bank statement CSV and automatically categorises each transaction against the SA105 property income boxes that HMRC uses on the property pages of a Self Assessment return. Rent receipts, maintenance costs, letting agent fees, insurance premiums, and mortgage interest are classified without you touching a formula. With 123 Sheets, every categorisation is done by you in your spreadsheet before the tool even becomes relevant.

• 2. No spreadsheet required — ever

  LandlordTaxAi is designed for landlords who do not want to maintain a spreadsheet. You upload a bank statement export, review the AI's categorisation suggestions on screen, approve or correct them, and submit. The spreadsheet — and all the discipline required to keep one accurate — is removed from the equation entirely. This is particularly valuable for landlords who have delayed engaging with MTD precisely because the spreadsheet approach felt too technical.

• 3. Purpose-built SA105 workflow

  Every screen, every category, and every submission step in LandlordTaxAi is built around the SA105 property income structure. There is no general accounting overhead — no VAT modules, no payroll, no invoicing features. The product does one thing: help UK landlords record and submit their property income accurately under MTD. 123 Sheets is similarly narrow in scope, but its narrowness is on the submission end rather than the categorisation end.

• 4. Faster quarterly workflow

  The time required to submit a quarterly update via 123 Sheets includes maintaining the spreadsheet throughout the quarter, reconciling it at quarter-end, and then bridging to HMRC. LandlordTaxAi compresses that to: download bank statement CSV from your bank, upload it, review AI suggestions, submit. For landlords with ten to fifty transactions per quarter, LandlordTaxAi's workflow typically takes under thirty minutes. The spreadsheet-plus-bridging approach often takes several hours of periodic attention.

Which tool is right for you?

The right choice depends on your existing habits, your appetite for manual administration, and whether confirmed HMRC recognition is a non-negotiable requirement today. Use the table below to find your profile.

For a broader comparison including seven MTD tools, see our best MTD software for landlords guide. For a full explanation of what MTD requires, read the MTD for landlords complete guide.

How to migrate from 123 Sheets to LandlordTaxAi

Switching from 123 Sheets mid-year is straightforward. Your previously submitted quarterly updates remain on record with HMRC regardless of which software you used to submit them — HMRC does not care about the tool, only the figures and the submission date.

1. Export year-to-date totals from your spreadsheet. Note the income and expense totals for each quarterly period already submitted, plus any unsubmitted current-quarter figures.
2. Create a LandlordTaxAi account. Sign up and add your rental properties. The onboarding process asks for the properties you are reporting on under MTD.
3. Upload your bank statement CSV. Download a CSV export from your bank covering the current quarter to date, then upload it to LandlordTaxAi. The AI begins categorising transactions immediately.
4. Review and correct AI categorisations. Work through the AI suggestions on screen. Anything the AI is uncertain about is flagged for your review. Corrections you make improve future accuracy.
5. Submit the next quarterly update via LandlordTaxAi. When the quarter ends, LandlordTaxAi compiles your figures and walks you through the HMRC submission steps. You do not need to touch 123 Sheets or your spreadsheet again.

Note: if you are mid-quarter when you switch, you will need to account for transactions that occurred before you started using LandlordTaxAi in that quarter. You can enter these manually or upload a CSV covering the full quarter including the pre-switch period. For help with your specific situation, use our MTD readiness checker.

Frequently asked questions