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Tax Compliance

VAT MTD Filing Guide: Everything Accountants Need to Know in 2026

A comprehensive guide to Making Tax Digital for VAT — covering registration, software requirements, filing deadlines, and common pitfalls for accountants.

ac-co.ai Teamac-co.ai Team2 min read

What Is Making Tax Digital for VAT?

Making Tax Digital (MTD) for VAT is HMRC's initiative requiring VAT-registered businesses to keep digital records and submit VAT returns using compatible software. Since April 2022, all VAT-registered businesses — regardless of turnover — must comply with MTD rules.

For accountants, this means ensuring every client's VAT workflow meets HMRC's digital requirements from record-keeping through to submission.

Key Requirements

Digital Record Keeping

Under MTD, businesses must maintain digital records of:

  • Business name, address, and VAT registration number
  • VAT scheme used (standard, flat rate, cash accounting, etc.)
  • Date, net value, and VAT rate for each supply made and received
  • Total output tax and input tax for each return period

Important: Digital records don't mean paperless. The underlying source documents (invoices, receipts) can still be physical — but the VAT accounting data must be held digitally.

Compatible Software

HMRC requires that VAT returns are filed through MTD-compatible software. The software must:

  1. Keep the required digital records
  2. Provide digital links between records (no manual re-keying)
  3. Submit VAT returns directly to HMRC via their API

Filing Deadlines

VAT return deadlines remain unchanged under MTD:

Return PeriodDeadline
Quarterly (standard)1 month + 7 days after period end
Monthly1 month + 7 days after period end
Annual accounting2 months after period end

Late filing triggers a points-based penalty system introduced in January 2023. Each late submission adds a penalty point; reaching the threshold (varies by filing frequency) results in a £200 penalty.

Common Pitfalls

The most common MTD compliance issue is broken digital links — where data is manually copied between spreadsheets or systems. HMRC expects an unbroken digital chain from source record to submitted return.

Solution: Use software that integrates directly with your accounting records. Tools like ac-co.ai automate the entire chain from transaction data through to HMRC submission.

2. Incorrect VAT Scheme Application

Flat rate scheme users sometimes miscalculate their flat rate percentage, especially after the first-year discount expires.

3. Missing Reverse Charge Entries

Services received from overseas suppliers often require a reverse charge entry. This is frequently missed in digital records, leading to both under-declared output tax and missed input tax recovery.

How ac-co.ai Helps

ac-co.ai simplifies MTD compliance by:

  • Automating VAT return preparation directly from your accounting data
  • Maintaining full digital links from transaction to submission
  • Validating returns before filing to catch common errors
  • Filing directly to HMRC through their official MTD API
  • Tracking deadlines and sending reminders before due dates

Getting Started

If you're an accountant looking to streamline MTD compliance for your practice, ac-co.ai integrates with your existing workflow. No migration required — connect your data sources and start filing.


Have questions about MTD compliance? Get in touch — we're here to help.