One of the first decisions you make — or more often, quietly default into — after VAT registration is how you account for your VAT. The choice between cash accounting and invoice accounting (sometimes called the standard VAT scheme) might sound like a technical detail, but it can make a meaningful difference to how much VAT you’re handing over to HMRC before you’ve actually been paid.

In our experience, a lot of small business owners don’t realise there’s a choice at all. They register for VAT, get set up on software, and the default kicks in. That’s not always wrong, but it’s worth understanding what you’re opting into and why the alternative might serve you better — particularly if you invoice B2B clients who take their time paying.

The core difference is about timing. Under invoice accounting (the standard approach), your VAT liability is triggered the moment you raise an invoice — regardless of whether your customer has paid you. You collect the VAT element when they eventually pay, but HMRC expects it on your next return based on invoice date.

Under the cash accounting scheme, the trigger shifts. You only account for VAT on a sale when the payment actually lands in your account. Similarly, you can only reclaim input VAT on purchases once you’ve paid your supplier — not when you receive their invoice.

In practice, this means:

• Invoice accounting: you could owe VAT to HMRC on money you haven’t yet received from your customers.
• Cash accounting: your VAT position mirrors your actual bank position far more closely.

For a business with reliable, prompt-paying customers, the difference is minimal. For a business with clients on 60- or 90-day payment terms, invoice accounting can feel like funding HMRC before you’ve been paid yourself — and that cash flow squeeze is very real.

The cash accounting scheme was designed with smaller businesses in mind, and its main appeal is straightforward: you don’t pay VAT until you’ve been paid. If a customer takes 60 days to settle an invoice, under the standard scheme you may already have handed that VAT to HMRC on your quarterly return before they’ve transferred a penny.

For trades businesses, contractors, and anyone doing project-based work with staged invoicing, this can create genuine pressure. You’re effectively acting as a short-term lender to your customers while simultaneously fronting VAT to the government.

There’s also a useful protection built into the cash scheme when it comes to bad debts. If a customer never pays you at all, you have no VAT liability on that invoice under cash accounting — because payment never arrived. Under the standard scheme, you’d need to wait at least six months before claiming bad debt relief, meaning you’ve already paid HMRC VAT on money you never received.

For businesses where late payment or bad debt is a genuine risk — which applies to quite a few of the trades and construction businesses we work with — that protection has real value.

Cash accounting isn’t the right fit for every business. There are situations where invoice accounting is more appropriate, or where the cash scheme’s advantages disappear.

If your customers pay you immediately — think retail, hospitality, or e-commerce — there’s no lag between raising an invoice and receiving payment. The cash flow benefit of the cash scheme largely vanishes in that scenario.

There’s also the input VAT side to consider. Under cash accounting, you can only reclaim VAT on supplier purchases once you’ve paid those suppliers. If your business carries significant stock or spends heavily on materials in advance of receiving customer payments, invoice accounting might actually give you a better VAT position — reclaiming input VAT sooner even if output VAT is also due sooner.

A few other scenarios where invoice accounting tends to make more sense:

• Your customers are all consumers (B2C), paying at point of sale.
• You tend to pay suppliers after you’ve been paid by customers, meaning the cash scheme’s input VAT timing doesn’t benefit you much.
• You’re on the VAT Flat Rate Scheme, which is mutually exclusive with cash accounting — you can’t use both.

Neither scheme is universally superior. It genuinely depends on your payment cycles and supplier terms.

The cash accounting scheme is available to businesses whose estimated VAT taxable turnover for the next 12 months is £1.35 million or less. Once you’re on it, you can stay until your VAT taxable turnover exceeds £1.6 million — so there’s a small buffer before you’re forced to leave.

There are some restrictions worth knowing before you decide:

• You cannot use the cash scheme alongside the Flat Rate Scheme. If you’re already on the flat rate, you’ll need to choose one or the other.
• Payment terms of six months or more are excluded. If you regularly invoice with extended credit terms, those transactions must stay outside the cash scheme.
• Invoices raised in advance — for example, annual retainers billed upfront — cannot be included in the cash scheme.
• You must also be up to date with your VAT returns and payments. If you’re behind with HMRC, you’re not eligible to join.

Switching between schemes is possible, but it does require care around the transition period — particularly making sure you don’t double-count or miss VAT on invoices that were raised under one scheme and paid under another. If you’re considering switching, it’s worth getting advice on how to handle that cleanly rather than assuming it will sort itself out in the software.