MTD Bridging Software: What It Is and Why It's All Most People Need

When you search for Making Tax Digital software, most of what you'll find is full accounting platforms: Xero, QuickBooks, Sage, FreeAgent. These are powerful products that handle invoicing, bank feeds, payroll, and everything else a growing business might need.

They're also £12-£25 per month, and for a lot of sole traders and landlords, they're far more than what's required. If you already keep your records in a spreadsheet and you just need to file quarterly updates with HMRC, there's a simpler (and much cheaper) option: bridging software.

What is bridging software?

Bridging software does one thing: it takes the financial data from your existing records and submits it to HMRC through their Making Tax Digital APIs. It's the "bridge" between your spreadsheets and HMRC's systems.

You continue keeping records however you already keep them - in Excel, Google Sheets, or any other spreadsheet. When it's time to file a quarterly update, you export your data (usually as a CSV file), upload it to the bridging software, review the figures, and submit. The software handles the technical communication with HMRC.

HMRC recognises bridging software as fully MTD-compatible. It appears on the same GOV.UK software list as Xero and Sage. There is no difference in compliance status between using bridging software and using a full accounting platform.

Bridging software vs full accounting software

The key question is simple: do you need accounting software, or do you just need MTD compliance? If you've been running your business for years with a spreadsheet and a Self Assessment return, bridging software lets you keep doing exactly that - with the addition of quarterly submissions.

How does the digital link work?

One of the MTD requirements is a "digital link" between your records and the software that submits to HMRC. This is the part that confuses people, but it's straightforward.

A digital link simply means the data must flow electronically. You can't look at a number in your spreadsheet and type it into a separate system. But you can export your spreadsheet to CSV and upload that file. You can also copy and paste values. The point is that the data transfer is digital, not manual re-entry.

When you upload a CSV to bridging software, that upload is the digital link. The software records which file was imported, creating an audit trail that satisfies HMRC's requirements.

How a typical quarterly submission works with bridging software

The entire process from login to confirmation typically takes five to ten minutes. Compare that to the hours many people spend fighting with full accounting software they don't fully understand.

Who should use bridging software?

Bridging software is the right choice if you already track your income and expenses in a spreadsheet and that system works for you. If you're a sole trader with straightforward finances - regular income, predictable expenses, no need for invoicing or bank feeds - bridging software does everything you need at a fraction of the cost.

It's also the right choice for landlords with one or a few properties. Rental income is typically simple to track (see our full landlord guide): rent received, mortgage interest, repairs, insurance, agent fees. A spreadsheet handles this easily, and bridging software connects it to HMRC.

Bridging software is probably not the right choice if you need invoicing, automatic bank reconciliation, multi-currency support, or VAT submissions alongside MTD for Income Tax. In those cases, a full accounting platform like Xero or QuickBooks makes more sense because the additional cost buys features you'll actually use.

What about AI-powered bridging software?

A newer category is bridging software with AI features. Instead of just passing your data through to HMRC, AI-powered bridging software can automatically categorise your transactions into the correct HMRC expense categories, flag potential errors before submission, and suggest allowable expenses you might have missed.

This is particularly useful if you upload a bank statement rather than pre-categorised data. The AI reads descriptions like "TESCO FUEL" and categorises it as a travel expense, or "AMAZON MARKETPLACE" and asks whether it's stock, office supplies, or personal.

The traditional bridging tools like 123 Sheets and VitalTax don't offer this - they assume your data is already categorised correctly. AI-powered options add a layer of intelligence without the complexity (or cost) of a full accounting platform.

What does bridging software cost?

The cheapest bridging software options start at around £20-£24/year including VAT. That's roughly £2 per month. Compare that to £12-£25 per month for full accounting software.

Some bridging tools also offer free tiers for users with simple needs, such as a single income source or income below a certain threshold.

The cost difference over a few years is substantial. If you're paying £15/month for Xero versus £20/year for bridging software, you're spending £160 more per year - over £800 extra across a five-year period - for features you may never open.

Is bridging software "real" HMRC software?

Yes. Bridging software that's listed on GOV.UK has been through the same HMRC approval process as every other MTD-compatible product. It uses the same APIs, submits data in the same format, and meets the same security requirements.

HMRC does not distinguish between submissions made via bridging software and those made via full accounting platforms. Your quarterly update arrives at HMRC the same way regardless of which type of software sent it.

The GOV.UK software list clearly shows which products are bridging tools and which are full accounting platforms, so you can make an informed choice. But in terms of compliance, both are equally valid.

Last updated March 2026. For the latest information on MTD requirements and compatible software, check GOV.UK.