Best Self-Assessment Tax Software for Landlords

You have two separate questions here: "Which software can technically file SA105?" and "Which one actually makes sense for you as a landlord in 2025-26, just before MTD hits?".

Snapshot: who each tool suits

Prices above are as advertised for 2025-26 tax year editions.

How each handles landlord-specific issues

GoSimpleTax

SA105 and multiple properties: auto-includes SA105 pages when you tick "property income", and gives a landlord-specific flow for UK property, FHL, commercial, and rent-a-room. Handles multiple properties and jointly-owned property with separate entries, and calculates each owner's share.

Expenses, Section 24 and CGT: categorised expense fields aligned to HMRC categories, with prompts for common landlord expenses and Section 24 finance cost treatment. Calculates tax due across bands and flags missing expense categories and potential errors. Includes CGT sections so you can report property disposals inside the return (not the separate 60-day CGT property return).

Guidance, accuracy and data: in-product tips aimed at landlords, error-checking, and HMRC-recognised filing direct from the web app. It does not pre-populate from HMRC APIs; you enter your own data but the system estimates tax due and flags issues.

Best for: hands-on landlords with one or more properties who want clear, landlord-specific prompts and a browser-based experience, and are willing to spend about GBP 70/year to avoid HMRC's bare-bones UI.

TaxCalc (Individual)

SA105 and multiple properties: desktop software (Windows/macOS) that lets you add SA105 pages to SA100 and fill them in with as much detail as you like. You handle multiple properties by listing them and aggregating totals; TaxCalc is flexible but not exclusively landlord-focused.

Expenses, CGT and checks: very strong calculation engine and "check and finish" routine that flags missing entries and inconsistencies. CGT handling is a key strength: you can enter disposal details, reliefs, and see how it feeds into the overall tax bill.

Guidance and cost: good on-screen help and context, but assumes basic familiarity with tax terms. GBP 42 for "TaxCalc 2026 Individual" covering up to 6 SA100 returns for that year, which is good value if you file for a spouse or other family members too.

Best for: people who do their own tax anyway, like having local copies of their returns, and may file more than one return each year. If you already understand SA105, TaxCalc is a power tool.

TaxScouts

Accountant-filed, not DIY software: you answer an online questionnaire, upload documents, and a human accountant prepares and files the return including property pages. Handles multiple properties, FHL, CGT on disposals, and more complex situations (non-resident, pensions, etc.).

Pricing and scope: for landlords, current pricing is from around GBP 169 per tax return (higher if more complex, but still fixed-fee). Includes checking your numbers, asking questions, and filing via HMRC agent software.

Best for: landlords who do not want to touch the forms, have more going on (salary, self-employment, CGT events) but still want a predictable, lower fee than a full offline practice.

HMRC free online Self Assessment

Functionality: lets you file SA100 online with property pages; SA105 as a separate paper form is mostly for paper filers now, but the online service captures the same data. No fancy guidance, no error-flagging beyond basic checks, and no optimisation of expenses.

Data and pre-population: will pre-populate some PAYE income and tax paid if HMRC holds it, but you still need to enter property income and expenses manually.

Best for: very simple cases where you are utterly confident in your numbers and happy to spend more time wrestling with the interface to save GBP 40-70 a year.

SimpleTax

Brand status: SimpleTax in the UK market was effectively folded into / rebranded as GoSimpleTax. Current landlord-focused marketing, pricing and HMRC recognition all sit under the GoSimpleTax name. Practically, if you see "SimpleTax" recommended on older forum threads, read that as "GoSimpleTax" in 2026.

When to use software vs a human accountant

Use DIY software (GoSimpleTax or TaxCalc) if:

You have straightforward personal BTL (one or several properties, all UK, no complicated partnerships) and you are comfortable keeping your own records.

You can invest a couple of hours once a year to enter data, read prompts, and understand basic Section 24 and expense categories.

You want to save on fees and you do not mind being responsible for the numbers.

Use TaxScouts or a traditional accountant if:

You have more complex situations: multiple disposals with CGT, incorporation, mixed-use property, non-resident issues, or property partnerships.

Large portfolios with refinancing, finance costs that need careful treatment, or planned changes like incorporation relief.

Your marginal tax rate is changing (recent Budget changes for property rates from April 2027 mean planning matters).

You are facing or expecting HMRC enquiries and want advice, not just form-filling.

The rule of thumb:

If your property side is 1-3 simple rentals and no sales, GoSimpleTax or TaxCalc is usually enough.

If you have 5+ properties, company structures, or have sold something this year, at least pay an accountant once to sanity-check things, then decide whether to stick with them or drop back to software.

What forums and blogs recommend (and where they are off)

Common recommendations

GoSimpleTax comes up repeatedly in landlord circles as the "landlord-friendly" cloud option, especially for accidental landlords.

TaxCalc is praised by more numerate users and accountants for its robustness and value if you file multiple returns.

TaxScouts is recommended to those who have left things late or had a messy year, where paying about GBP 169 once is better than guessing.

Common mistakes

"HMRC online is fine; you do not need anything else": it works, but it gives you almost no help on what you can claim or how Section 24 works. Many underclaim or mis-categorise expenses.

"Software will find you clever tax planning": GoSimpleTax and TaxCalc are calculators and form fillers, not tax planners. They do not replace advice on incorporation, CGT strategies, or transfer of beneficial interest.

Confusing current Self Assessment with MTD: you need something that can file a traditional SA return for 2024-25 and 2025-26, and then an MTD-compatible tool from April 2026 onwards if your income is above GBP 50,000.

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