With a £90,000 VAT registration threshold, many UK businesses might wonder whether to register voluntarily. Understanding how to balance output and input VAT can help optimise cash flow and avoid costly mistakes with HMRC.

The current VAT registration threshold for businesses is £90,000 in taxable turnover. However, businesses below this threshold can still opt for voluntary VAT registration.

VAT registered businesses charge VAT on their sales, known as output VAT, while also paying VAT on most of their purchases, referred to as input VAT.

The output VAT is collected from customers on behalf of HMRC and must be regularly paid over to HMRC. However, businesses can deduct the input VAT on most (but potentially not all) goods and services purchased from their output VAT liability to HMRC.

This calculation usually results in a VAT payment that is due to HMRC. If the input VAT exceeds the output VAT, HMRC will owe you a refund of overpaid VAT.

HMRC’s guidance states that the following must be included on your VAT return:

• your total sales and purchases
• the amount of VAT you owe
• the amount of VAT you can reclaim
• the amount of VAT you’re owed from HMRC (if you’re reclaiming VAT on business expenses)

It's important to include VAT on the full value of your sales, even if:

• You receive goods or services instead of money (e.g., part-exchange)
• You have not charged VAT to the customer (the full price charged is treated as including VAT).

Please note, you cannot charge VAT to your customers or claim back the input tax you have paid to suppliers unless you have formally registered for VAT.