MTD Bridging Software Explained: Can You Keep Using Excel?

If you have spent years tracking your rental income and expenses in a carefully built Excel spreadsheet, the thought of abandoning it for new software probably fills you with dread. The good news is that HMRC does not actually require you to stop using spreadsheets altogether. The less good news is that you cannot simply file your spreadsheet data to HMRC by typing numbers into an online form. This is where bridging software enters the picture.

Bridging software acts as a translator between your existing spreadsheets and HMRC's MTD systems. It reads your data from Excel or another spreadsheet application and submits it digitally via HMRC's API — no manual re-keying allowed. For some landlords, this sounds like the perfect compromise: keep the spreadsheet you know, add a bridging tool on top, and carry on as before.

But is it really that simple? In this guide we will explain exactly how bridging software works, what HMRC's digital links requirement means in practice, what bridging tools typically cost, and why most landlords find that purpose-built MTD software is actually easier and cheaper in the long run. Whether you are a committed spreadsheet user or just exploring your options, this article will give you the full picture.

What Is Bridging Software?

Bridging software is a piece of software that sits between your spreadsheet and HMRC. Its sole job is to take data from your existing records — typically an Excel or Google Sheets file — and submit it to HMRC through the Making Tax Digital API. Think of it as a digital postman: it does not change your data or help you prepare it, it simply delivers it in the format HMRC requires.

The flow works like this:

• Step 1: You maintain your income and expense records in your spreadsheet, exactly as you do today.
• Step 2: You structure your spreadsheet so the bridging software can read it — this usually means putting totals in specific cells or following a template the bridging tool provides.
• Step 3: At the end of each quarter, you open the bridging software and point it at your spreadsheet.
• Step 4: The bridging software reads the relevant figures (total income, total expenses, and any required breakdowns).
• Step 5: The software formats these figures into the structure HMRC's API expects.
• Step 6: The software submits the data to HMRC and returns a confirmation receipt.

Crucially, bridging software does not check whether your figures are correct. It does not categorise your expenses, warn you about missing data, or flag errors in your spreadsheet. It is purely a transmission mechanism. The accuracy of what gets submitted to HMRC is entirely down to you and the quality of your spreadsheet.

How the Digital Links Requirement Works

HMRC's MTD rules include a requirement that has caught many landlords off guard: digital links. The principle is straightforward — data must flow digitally from its point of original entry all the way through to the submission to HMRC, with no manual re-typing at any stage.

Here is what this means in practice:

• If you record a £450 gas bill in cell B14 of your spreadsheet, the bridging software must read that figure directly from cell B14. You cannot look at cell B14, note that it says £450, and then type £450 into the bridging tool.
• If your spreadsheet calculates total expenses using a SUM formula, the bridging software must read the result of that formula. You cannot manually calculate the total on a calculator and enter it separately.
• If you copy data from one spreadsheet to another as part of your workflow, the copy must be done digitally (copy-paste, formula link, or import function). You cannot print one spreadsheet and re-type the values into another.

The digital links rule applies to every step in your data journey. If you use one spreadsheet to record transactions, a second spreadsheet to summarise them by quarter, and then bridging software to submit the quarterly totals, every link in that chain must be digital. A single manual re-typing step breaks the chain and makes your process non-compliant.

The Soft Landing Period

When MTD for VAT was introduced, HMRC allowed a soft landing period during which the digital links requirement was not strictly enforced. Businesses were expected to have digital record keeping and to submit via the API, but HMRC accepted that some manual data transfer steps might still exist while businesses transitioned.

HMRC has indicated a similar approach for MTD for Income Tax. During the initial period after your MTD start date, HMRC is expected to take a proportionate approach to digital links enforcement. This means:

• You must keep digital records from day one — paper-only records are not acceptable even during the soft landing period.
• You must submit quarterly updates via compatible software (either native MTD software or bridging software) from the start.
• If you have a few manual copy-paste steps in your spreadsheet workflow, HMRC is unlikely to penalise you immediately — but you are expected to be working towards fully digital links.
• The soft landing period is not a permanent exemption. HMRC will eventually enforce digital links fully, and at that point your entire data chain must be unbroken.

The exact duration of the soft landing period for MTD for Income Tax has not been definitively confirmed at the time of writing. For MTD for VAT, it lasted approximately one year. Landlords should plan on the assumption that digital links will be fully enforced within 12 to 18 months of their MTD start date.

Popular Bridging Tools and Their Costs

Bridging tools vary in price and functionality, but they broadly fall into three categories:

Bridging Software vs Native MTD Software

This is the comparison most landlords need to see before making a decision. Bridging software and native MTD software both get your data to HMRC, but they differ significantly in everything else.

When Bridging Software Makes Sense

Despite the limitations, there are specific scenarios where bridging software is a reasonable choice.

• You have a single rental property with simple income and expenses, and you already have a well-structured spreadsheet that you are confident is accurate.
• You are an accountant or bookkeeper who manages spreadsheets professionally and can ensure digital links compliance across your data workflow.
• You are already using a business accounting system that does not support MTD for Income Tax directly but can export data in a format bridging software can read.
• You are in the first year of MTD compliance and want to start with minimal disruption while you evaluate native software options — bridging can serve as a transitional tool.
• You have highly customised reporting needs that no off-the-shelf software supports, and your spreadsheet is the only way to produce the analysis you need.

In these cases, bridging software lets you meet the basic MTD requirement (digital submission via the API) without changing your existing workflow. But for most of these scenarios, the advantage is short-term convenience rather than long-term efficiency.

When Bridging Software Does Not Make Sense

For the majority of landlords, native MTD software is the better choice. Bridging software is particularly poor fit in these situations:

• You own multiple properties — the spreadsheet complexity scales quickly and the risk of errors multiplies with each property you add.
• You have HMOs or multi-unit properties — tracking room-level income and shared expenses in a spreadsheet is error-prone and difficult to audit.
• You are not confident in your spreadsheet skills — bridging software provides zero hand-holding. If your formulas are wrong, your HMRC submission will be wrong.
• You want to reduce time spent on admin — bridging software adds a step to your process (the quarterly submission) without reducing any of the existing work.
• You are concerned about compliance risk — bridging software submits whatever you give it, including errors. Native software validates your data before it goes anywhere near HMRC.
• You share property management with a partner or agent — spreadsheets with bridging tools are very difficult to use collaboratively without risking version conflicts and broken digital links.

The Hidden Costs of Keeping Excel

The headline cost of bridging software looks attractive — many options are free or under £100 per year. But the true cost of the spreadsheet-plus-bridging approach includes several hidden factors that landlords frequently underestimate.

Let us put some rough numbers on it. If your time is worth £25 per hour (a conservative estimate for a property investor) and you spend 12 hours per year on spreadsheet maintenance and quarterly submissions, that is £300 of your time — more than the cost of most native MTD software subscriptions. And that is before accounting for the cost of correcting any errors.

Making the Switch From Spreadsheets

If you have decided that native MTD software is the right move, the transition does not have to be painful. Here is a practical approach to migrating from spreadsheets.

• Start at a natural break point — the beginning of a new tax year (6 April) or the start of a new quarter. This avoids having to split a period across two systems.
• Export your existing spreadsheet data as a CSV file. Most MTD software, including Latch, can import transaction data from CSV files, mapping your columns to the correct fields.
• Set up your properties and units in the new software first, before importing transactions. This ensures imported income and expenses are linked to the right properties.
• Import historical data if you want continuity, or start fresh if your existing records are messy. There is no MTD requirement to import historical data — HMRC only requires digital records from your MTD start date onwards.
• Run both systems in parallel for one quarter if you want confidence. Record transactions in both your spreadsheet and the new software, then compare the quarterly totals. Once they match, you can retire the spreadsheet.
• Keep your old spreadsheets archived — do not delete them. HMRC can enquire into returns for up to four years (longer in cases of negligence or fraud), so your historical records should be preserved even after you switch systems.

Latch makes this transition straightforward. You can set up your properties and units to match your existing portfolio structure, import historical transactions from CSV if needed, and start recording new income and expenses immediately. The free plan includes core MTD compliance features — income and expense tracking, manual categorisation, and quarterly update preparation — so you can try the software at no cost before committing to a paid plan.

Paid plans from £20 per month add AI-powered expense categorisation, which is particularly valuable during the transition. Instead of manually categorising every imported transaction, the AI can suggest categories based on the description and amount, saving hours of setup time. Unlimited properties and advanced reporting are also included in paid plans, which becomes important as your portfolio grows beyond a handful of properties.

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