Most people budget £30 for a custom cake, then open a quote for £90. A custom birthday cake in the UK usually costs between £40 and £150, depending on size, decoration and how early you order.

Plain buttercream cakes sit at the bottom of that range. Sculpted, tiered or heavily decorated cakes sit at the top, and some go well beyond it. Here is where the money goes, so you can judge whether a quote is fair.

Custom birthday cake cost in the UK by size

Prices rise in London and the South East. As a rough guide for a round sponge with simple decoration:

• 6 inch, serves 8 to 10: £40 to £60
• 8 inch, serves 15 to 20: £60 to £90
• 10 inch, serves 25 to 30: £90 to £130
• Two tiers, serves 40 or more: from £150

Servings depend on slice size. Party slices are smaller than dessert portions, so ask your baker which one they mean.

Where the extra money goes

Design pushes the price up faster than flavour does. Fondant costs more than buttercream because it takes longer to roll, smooth and finish by hand.

Hand-modelled figures, sugar flowers and sculpted shapes can each add £20 to £100 or more. A baker who spends three hours on one figure has to charge for those hours. Gluten-free and vegan cakes also tend to carry a small premium, as the ingredients cost more and some bakers need separate preparation space.

Questions people ask before ordering

Is a home baker cheaper than a bakery?

Often, yes. Check that they are registered with their local council and have a food hygiene rating before you pay a deposit.

How far ahead should I order?

Many bakers ask for two to four weeks. Weekends in school holidays fill first, and rush orders can cost extra.

Is the deposit refundable?

Policies differ. Read the terms before you pay, because many small bakers keep deposits if you cancel late.

Ways to pay less

1. Choose buttercream instead of fondant.

2. Order a small decorated cake for the photos and a plain sheet cake for slicing in the kitchen.

3. Pick one eye-catching feature, such as a topper, rather than three.

4. Collect the cake yourself. Delivery is usually charged by distance.

5. Book early, so you avoid rush fees.

Mistakes that push up the bill

Sending a photo of a £300 wedding-style cake and asking for a copy at £80 is the most common one. Bakers price what they see, not what you hope to spend.

Leaving out your guest numbers is another. The baker then quotes for a safe size, and you pay for cake nobody eats.

Changing the design after sign-off also costs money. A new colour scheme or extra tier can mean new materials and lost time, and most bakers charge for both.

Finally, check what the quote includes. Some bakers charge separately for the cake board, boxes and candles.

Get an accurate quote on the first message

Before you contact a baker, write down four things: the date, the number of guests, the design and your budget. Send them together in your first message. That gets you a real answer to how much a custom birthday cake costs in the UK for your party, and it saves several rounds of back and forth.