Broken Digital Links: The MTD Rule That Quietly Catches Businesses Out

A business can file every VAT return on time, through recognised software, and still be breaking the Making Tax Digital rules without knowing it. The reason is a requirement most people never notice when they sign up: the data has to flow from the original record to the figure on the return without anyone re-typing it along the way. Where a person keys a number out of one system and into another, that manual step is a broken digital link, and it is a compliance failure even if the final return is correct to the penny. The wider framework of digital record-keeping and penalty exposure is set out across the MTD and VAT penalty rules, and broken links are the part of it that catches otherwise careful businesses.

The idea behind the rule is straightforward. HMRC wants an unbroken trail from the point a transaction is recorded to the point it lands in the boxes of the return, so that the numbers cannot be quietly altered or mistyped between systems. The trail can pass through as many pieces of software as you like, but every hop between them has to be a digital link rather than a human copying figures across.

What counts as a digital link

A digital link is a transfer of data between two programs that happens without manual intervention. Once a figure is entered in the first place, it should move onwards electronically. The common forms that qualify are all ways of moving data machine to machine.

• An API connection between two applications, for example a till or online shop feeding sales straight into the accounting package.
• Importing and exporting data as a file, such as a CSV or XML file produced by one system and read by another, provided no one edits the figures in between.
• Bridging software that reads cells directly from a spreadsheet and submits them, where the spreadsheet itself is the digital record.
• Linked cells within or between spreadsheets, where a formula pulls a value from one sheet to another rather than someone typing it.

The thread running through all of these is that a value is entered once and then referenced, not re-entered. As soon as a human reads a number off a screen or a printout and types it somewhere else, the chain is broken at that point.

The everyday actions that break the link

Broken links are rarely deliberate. They creep in through habits that feel harmless, usually a quick manual step to bridge two tools that do not talk to each other. The typical culprits are familiar to most finance teams.

• Reading a total off one system and re-typing it into the VAT return or into a summary spreadsheet.
• Copying figures out of the accounting software into an email or a document, then keying them back in elsewhere to file.
• Printing a report and manually entering the numbers into a separate return-preparation tool.
• Cutting and pasting values between spreadsheets where the paste replaces a formula with a static number that someone has effectively transcribed.

Where spreadsheets sit in the rules

Spreadsheets are still allowed under Making Tax Digital, which surprises people who assume the regime forced everyone onto cloud software. You can keep your digital records in a spreadsheet and file through bridging software that submits directly from it. What you cannot do is use the spreadsheet as a staging post where numbers are typed in by hand from another system. If sales data arrives in the accounting package and you then manually summarise it into a spreadsheet before filing, that summary step is the break. This sits on top of the wider Making Tax Digital for VAT obligations to keep records digitally and file through software, and a Making Tax Digital service is the practical route to getting the whole chain set up properly for a Harrow business.

HMRC describes the requirement and the acceptable forms of link in its guidance on the digital record keeping rules for VAT, which is the reference point when you are checking whether a particular transfer qualifies. The professional body ICAEW also maintains a practical VAT technical resource that covers the digital links question for members and their clients.

How to find and close the gaps

Fixing broken links is usually a matter of mapping the journey your numbers actually take and replacing every manual hop with an automated one. The work is more about process than software spend.

None of this changes the VAT figures you report; it changes how they travel. A clean digital chain also tends to remove a source of ordinary error, because the numbers that reach the return are the same ones that were recorded, not a re-keyed copy of them. The same accuracy discipline matters when you actually prepare the boxes on your VAT returns, where a re-keyed figure is exactly the kind of thing that goes wrong.

Common questions about broken digital links

Am I compliant just because I file through software?

Not necessarily. Filing through recognised software satisfies the submission requirement, but Making Tax Digital also demands an unbroken digital trail behind it. If a figure is manually re-keyed at any point between the original record and the return, there is a broken link regardless of how the return is finally submitted.

Can I still use spreadsheets?

Yes. Spreadsheets are permitted as digital records and can be filed through bridging software. The restriction is on manually copying numbers into or out of them from another system. If the spreadsheet is fed and read digitally, it is fine; if it is a place where figures are typed in by hand from elsewhere, that is the break.

What is the penalty for a broken link?

A broken digital link is a breach of the MTD requirements and can attract a penalty, applied to the failure itself rather than to the accuracy of the return. Because the exposure does not depend on the numbers being wrong, the practical answer is to remove manual hops from the chain rather than rely on the return happening to be correct.

Broken digital links are the quiet compliance risk of Making Tax Digital, because they sit in the plumbing between systems rather than on the face of the return. If you are unsure whether your data really travels digitally from record to filing around Harrow, tell us which systems you use and how the numbers move between them through the form on this page, and we will map the chain, point out any manual step that breaks it, and set up the digital links so the trail holds up under inspection.