High-Street shops are braced for a flood of consumers demanding refunds following the government’s cut in Vat last week.

Although the reduction from 17.5% to 15% is officially implemented tomorrow, you may be able to ask for money back if you have already made a full or partial payment for your goods or services, but haven’t yet received them.

On a £20,000 kitchen, for example, the savings could be more than £400. Even if you have already paid a deposit, you could still renegotiate on the full price and get money back on the amount you’ve paid.

The dash for refunds comes as retailers are resorting to guerrilla sales to boost profits. Last week, Marks & Spencer held a one-day sale of 20% off, while House of Fraser was offering up to 40% off some products for two days.

This weekend, Boots is giving up to 50% off on some ranges while Selfridges shoppers can enjoy a 20% cut using online discount vouchers.

John Lewis, which started offering the Vat reduction to customers at the tills on Friday, confirmed that anyone who has already paid for goods, but has not yet received them will be offered a refund on the extra Vat they have paid.

We offer a guide.

Is everyone offering a Vat refund?

Other retailers may have different policies because they levy Vat on orders at different times. These “tax points” can occur when an order is made, when it is received or when a payment is processed.

John Lewis says its tax point occurs when a customer receives their goods. Others, such as House of Fraser, say they cannot offer a refund on Vat because it applies the charge when a customer makes an order.

Ronnie Ludwig of chartered accountants Saffery Champness said: “Sellers have discretion to apply the new rate of 15% or the old rate of 17.5% depending on that tax point, so customers who have ordered goods or contracted for services may find it useful to discuss this with the seller, especially if an interim invoice has recently been issued.”

If you have paid a deposit for ongoing work — such as a new kitchen — you may be able to negotiate a lower final payment if you settle the balance from tomorrow onwards.