Making Tax Digital Accounting Software: The Switching Cost Nobody Quotes

When does a £12-a-month subscription become a £600-a-year decision you can never reverse? The moment you import three years of transaction history into making tax digital accounting software and realise the export button does not exist.

This post is not a comparison of features. There are plenty of those already. This is about the costs that never appear in the pricing table: the time you spend migrating, the data you cannot take with you when you leave, and the quiet financial gravity that keeps sole traders locked into software long after it has stopped being the right fit. If you are choosing making tax digital accounting software for the first time, or wondering whether to switch, this is what you need to price in before you decide.

The Price You See Versus the Price You Pay

Take a sole trader electrician turning over £65,000 a year. He needs to track income, log deductible expenses, submit four quarterly updates to HMRC under MTD for Income Tax, and file an end-of-period statement plus a final declaration annually. That is six digital interactions with HMRC per year, a stack of receipts, and a mileage log.

The software he is considering charges £14 a month on the entry plan. That sounds reasonable. But here is what the pricing page does not show:

Setup time. Connecting a bank feed, categorising opening balances, configuring VAT settings if applicable, and learning the interface costs the average non-accountant sole trader between four and eight hours in the first month, according to user research published by the Federation of Small Businesses. At £35 an hour (a conservative self-employed rate), that is between £140 and £280 of time that never shows up in the subscription cost.

Annual price increases. The major MTD accounting software vendors have increased pricing by an average of 15–20% year-on-year since 2021, a trend that shows little sign of reversing as the MTD rollout drives captive demand. A plan that costs £14 a month today could reasonably cost £19–£22 within two years.

The feature tax. Most entry-level plans are deliberately limited to push users onto mid-tier packages. Missing features like bank reconciliation, mileage tracking, or multi-category expense splits often appear only on plans costing £25–£35 a month. The electrician who signs up for £14 and upgrades within three months has paid the feature tax that the vendor's product team designed into the journey.

The Lock-In Nobody Talks About at Sign-Up

The most significant hidden cost of making tax digital accounting software is not financial. It is structural. Once you have used a platform for 12 months, your transaction history, categorisation logic, and tax calculations live inside that vendor's database. What happens when you want to leave?

This is where the HMRC approved software list offers no protection at all. HMRC's approval process certifies that software can communicate with its systems. It says nothing about whether you can extract your own data in a portable format.

A survey of the most widely used MTD accounting platforms reveals the following:

• Several major vendors allow CSV export of transaction lists but do not export categorisation, tax codes, or the reconciliation status of individual entries. Importing that CSV into a new platform means re-doing months of bookkeeping work.
• At least two prominent platforms export to proprietary formats that are only readable by their own software, or by paying a third-party migration service.
• One well-known provider charges a data extraction fee if you cancel and request a full export archive.

This is not an accident. It is a retention strategy. The economics of MTD software complexity are built on the assumption that switching costs will keep users paying even when better options emerge.

For a sole trader who has used the same platform for three years, the realistic switching cost including migration time, potential data re-entry, and the learning curve on a new interface can easily exceed £400–£500. That is a powerful reason to stay. It is also a reason to choose carefully before you start.

What Sole Traders Actually Need from MTD Accounting Software

Before evaluating any platform, it helps to separate what HMRC actually requires from what software vendors want you to believe you need.

HMRC requires:

1. Digital records of income and expenses (no specific format, just digital)
2. Quarterly updates submitted via compatible software
3. An end-of-period statement
4. A final declaration

HMRC does not require:

• Double-entry bookkeeping
• Balance sheets
• Profit and loss statements (though these are useful)
• Multi-currency support
• Payroll integration
• Inventory management
• Project tracking

Yet the majority of making tax digital accounting software packages bundle all of the above into a single product and price it accordingly. A plumber earning £72,000 a year with no employees and no VAT registration does not need payroll. He does not need inventory management. He needs income tracking, expense categorisation, receipt capture, and a clean route to HMRC's servers four times a year plus a final declaration.

When you strip MTD compliance back to what a sole trader actually requires, the right software becomes significantly simpler and significantly cheaper. This is precisely why dedicated MTD apps exist alongside the legacy accounting platforms, and why they are worth serious consideration before you commit to a bloated subscription.

The True Cost Calculation: A Worked Example

Let us put concrete numbers on this for the electrician earning £65,000.

Option A: Mid-tier legacy accounting software

• Monthly cost: £28 (after upgrading from entry plan for bank reconciliation)
• Annual cost: £336
• Setup time: 6 hours at £35/hour = £210
• Year 1 total cost: £546
• Year 3 cost (assuming 18% annual increase): approximately £470/year
• Three-year total: approximately £1,400

Option B: Purpose-built MTD app

• Monthly cost: £10
• Annual cost: £120
• Setup time: 1–2 hours = £35–£70
• Year 1 total cost: £155–£190
• Three-year total (modest price increases): approximately £400

The difference over three years is approximately £1,000. For an electrician earning £65,000, that is real money. It is also a difference that is invisible if you only compare the £28 versus £10 monthly headline.

None of this means legacy accounting software is wrong for every sole trader. If you have a bookkeeper who uses it, if you have employees requiring payroll, or if your accountant is already on the platform and you benefit from shared access, the additional cost may be justified. But if you are a time-poor tradesperson managing your own books with no employees and straightforward income, the question of what you are overpaying for deserves an honest answer before you sign up.

When Switching Does Make Sense

If you are already on a legacy platform and considering moving to something leaner before MTD for Income Tax becomes mandatory, the calculation depends on timing.

Moving now, before April 2026, gives you time to establish clean records on a new platform without the pressure of an imminent compliance deadline. You can run both systems briefly if needed, ensuring no transaction history is lost. You also avoid the migration chaos that will predictably affect thousands of sole traders in early 2026 when the MTD deadline arrives and support queues at every software vendor become unmanageable.

Switching MTD software without the chaos is possible, but it requires a clean break at a logical point: either the start of a new tax year (6 April) or the start of a new quarter. Migrating mid-quarter is the single biggest source of duplication errors and missing records.

The practical checklist before you switch:

Before You Leave Your Current Platform

• Export every transaction record in CSV format, dated and categorised
• Download or print your last two tax year summaries
• Screenshot your current category structure so you can replicate it
• Note any recurring bank rules you have set up
• Record your opening balances as at the switch date

Before You Commit to a New Platform

• Confirm it is on HMRC's approved MTD software list
• Test the data import function with a sample CSV before migrating everything
• Check the export policy: can you get all your data out, in what format, and at what cost?
• Read the pricing page for what is excluded from the base plan, not just what is included
• Check whether price lock guarantees exist (most do not)

The Question Every Sole Trader Should Ask First

The making tax digital accounting software market is large, crowded, and deliberately complex. The vendors who spend most on marketing are, almost by definition, the vendors with the most to recoup through subscription revenue. That does not make them the best fit for a sole trader whose compliance needs are, in reality, quite modest.

The question worth asking before any demo call or free trial is not "which software has the most features" but "which software will cost me the least in money and time over the next three years, and let me leave if something better comes along?"

Answering that question requires looking past the pricing page, testing the data export before you commit, and being honest about whether you need payroll software, inventory tracking, and multi-currency support or whether you need an income log, an expense tracker, and a reliable quarterly submission to HMRC.

For the majority of sole traders this post is written for, the answer points firmly toward simplicity. The MTD quarterly submission is identical whether you send it from a £30-a-month legacy platform or a £10-a-month purpose-built app. HMRC receives the same data either way. The only difference is what you pay for the privilege.

You opened this post wondering about making tax digital accounting software. The honest answer is that the right software is the one you will actually use, can afford to keep, and can leave without penalty when something better arrives. If your current or prospective software fails any of those three tests, that is the number worth calculating before the monthly fee.