If you are VAT-registered and finding the quarterly filing process stressful, confusing, or just relentlessly time-consuming, this guide explains exactly what is involved and what your options are. You will leave knowing what HMRC now requires, where most small businesses go wrong, and what it looks like to hand the whole thing over to a bookkeeper.

Why handling VAT returns is harder now

The rules around VAT filing changed significantly on 31 March 2026. HMRC closed its online filing portal on that date, which means you can no longer log into your Government Gateway account and submit a return manually. Every VAT-registered business must now use MTD-compatible software to file.

HMRC automatically enrolled all VAT-registered businesses into Making Tax Digital for VAT from 2026, removing the option to opt out unless you apply for an exemption. If you have been filing through the old portal and have not yet set up compatible software, your next return deadline is already at risk.

Where most small businesses get VAT returns wrong

Most errors are not the result of deliberate mistakes. They come from a combination of incomplete records, confusion about what qualifies for input tax recovery, and software that has not been set up correctly. HMRC estimates that compliance measures target around one-third of the small business tax gap, which gives a sense of how widespread these problems are across the UK.

Claiming VAT on non-qualifying expenses

One of the most frequent errors is claiming input VAT on purchases that do not qualify, such as client entertainment or items with mixed personal and business use. HMRC does challenge these during compliance checks. Incorrectly reclaimed VAT can result in assessments that demand repayment, plus interest.

Mismatched figures between your software and your return

When your Xero data is not fully reconciled before a return is prepared, the figures pulled through to the return can be wrong. This is particularly common when bank feeds are not kept up to date or when invoices are posted to incorrect VAT codes. The return looks complete but the numbers do not reflect your actual trading.

What the VAT return process actually involves

A VAT return requires you to report the total VAT you have charged to customers, the total VAT you have paid on business purchases, and the difference between the two. If you have charged more than you have paid, you owe HMRC the difference. If you have paid more than you have charged, HMRC owes you a refund. That is the calculation at the core of every return, regardless of your industry or turnover.

1. Step 1: Reconcile your records. Before any figures are submitted, your bank statements, sales invoices, and purchase receipts need to be matched against your accounting software. In Xero, this means all bank transactions are categorised and reconciled for the full quarter.
2. Step 2: Review the VAT return figures. Once your records are reconciled, the VAT return is generated from your software. Each box on the return corresponds to a specific category of VAT. Box 1 is the VAT you owe on sales. Box 4 is the VAT you are reclaiming on purchases. Each figure needs to be checked against your underlying data before submission.
3. Step 3: Submit through MTD-compatible software. Since 31 March 2026, the return must be submitted directly through software that is linked to HMRC via the MTD API. Xero supports this. Once submitted, HMRC confirms receipt and your payment deadline is shown in your account. The deadline to pay is typically one month and seven days after the end of your VAT period.

The process sounds straightforward written out like this. In practice, it takes longer when records are incomplete, when transactions have not been categorised correctly, or when you are unfamiliar with which VAT codes apply to your type of business. That is the point at which most business owners decide the quarterly exercise is no longer worth doing themselves.

Comparing the cost of DIY against using a bookkeeper

The honest comparison is not just about the fee. It is about what you are actually spending when you handle VAT returns yourself: the time it takes, the risk of an error that HMRC later queries, and the mental load of managing quarterly deadlines on top of everything else your business demands. A bookkeeper who handles VAT as part of a fixed monthly arrangement removes all three.

What to do before your next VAT deadline

If your next return is coming up and your records are not in order, there are a few things you can do right now to reduce the risk of filing something incorrect. These steps apply whether you are handling the return yourself or handing it to a bookkeeper.

• Log into Xero and check that all bank transactions up to the end of your last VAT quarter are reconciled. If there are unreconciled items sitting in the feed, those will affect your return figures. Clear the backlog before the return is prepared.
• Check which VAT stagger group you are in. Your VAT certificate or your HMRC business tax account will show your period end dates. Knowing your exact deadline means you are not guessing, and it gives you time to get records in order rather than rushing at the last minute.