Simplified Expenses: What They Really Mean (And When to Use Them)

Simplified expenses sound like a dream. Less paperwork. Fewer calculations. HMRC-approved shortcuts. What’s not to like?

Well… like most things in tax, they’re helpful when used properly. But they’re not always the best option and they don’t suit every situation. Let’s break down what simplified expenses actually are, how they work, and when they might (or might not) be right for you.

Who can use simplified expenses?

Simplified expenses are available to sole traders and partnerships (as long as all partners are individuals).

So if you’re self-employed and running your business as a sole trader, this is for you.

What are simplified expenses?

Simplified expenses are flat-rate methods of claiming certain business costs instead of working out the exact amounts. Instead of adding up every receipt, bill or percentage, HMRC lets you use set rates for specific things. They’re designed to:

• Save time

• Reduce admin

• Make things easier

(Sometimes they do exactly that!)

What can you use simplified expenses for?

There are three main areas:

1. Working from home

If you run your business from home, you can claim a flat monthly amount based on the number of hours you work from home.

HMRC flat rates:

• 25–50 hours/month → £10

• 51–100 hours/month → £18

• 101+ hours/month → £26

2. Vehicle expenses (mileage rates)

Instead of claiming fuel, insurance, repairs and other running costs separately, you can use HMRC’s mileage rates.

• Cars/vans:

  • 45p per mile (first 10,000 miles)

  • 25p per mile (over 10,000 miles)

• Motorcycles: 24p per mile

Example

You drive 5,000 business miles in a year: 5,000 × 45p = £2,250 claim

No need to track fuel receipts or calculate percentages.

3. Living at your business premises

This applies if you both:

• Live and run your business from the same place(e.g. a pub, guesthouse, or shop with accommodation)

You can use flat rates to separate personal and business costs.

Monthly adjustments:

• 1 person → £350

• 2 people → £500

• 3+ people → £650

This amount is deducted from total household costs to leave the business portion.

Simplified vs actual costs: which is better?

This is where it gets interesting. Simplified expenses are:

• Easier

• Quicker

• Less admin

But they’re not always the most tax-efficient.

Example: working from home

If your household bills are high and you use a large portion of your home for business, the flat rate might underclaim compared to actual costs. On the other hand, if your usage is low or you want to keep things simple, the flat rate works well.

Example: vehicle use

If you:

• Drive a fuel-efficient car

• Have low running costs

Mileage rates can be generous. But if:

• You have high costs

• Expensive repairs

• High insurance

Actual costs might give a bigger claim.

Important rules and restrictions

This is where people can trip up.

❗ You can’t mix methods for the same thing

If you use mileage rates, you cannot also claim fuel or repairs separately. It’s one method or the other.

❗ You must stick with your choice (for vehicles)

Once you choose simplified expenses (mileage) for a vehicle, you must continue using that method for that vehicle. You can’t switch back and forth each year to maximise your claim.

❗ You still need records

Even though it’s “simplified”, you still need:

• Mileage logs

• Evidence of hours worked from home

• Proof of business use

HMRC still expects reasonable records just not detailed calculations.

❗ It’s not always the best option

Simplified doesn’t mean optimal. Sometimes:

• You’ll claim less

• You’ll miss out on legitimate expenses

It’s about balancing simplicity with accuracy.

Common misunderstandings

❌ “Simplified expenses are always better”

Not necessarily, they’re just easier.

❌ “I can claim everything anyway”

No only specific categories qualify.

❌ “I can switch whenever I like”

Not always especially for vehicles.

❌ “I don’t need to keep records”

You still do just less detailed ones.

A quick real-world example

Emma is a self-employed consultant who:

• Works from home part-time

• Drives to client meetings

• Wants to keep things simple

She chooses:

• Flat-rate home working (£18/month)

• Mileage rates for her car

This gives her:

• Easy record keeping

• Predictable claims

• Less admin

But if her circumstances changed (more travel, higher costs), reviewing those choices would be important.

So… should you use simplified expenses?

It depends. They’re a great option if you:

• Want to keep things simple

• Have relatively low or average costs

• Don’t want to track every detail

They may not be ideal if you:

• Have higher-than-average costs

• Want to maximise your tax efficiency

• Are happy to keep more detailed records

Final thoughts

Simplified expenses are exactly what they sound like, a simpler way of claiming certain costs.

They can save time, reduce admin, and make bookkeeping feel a bit more manageable. They’re not a one-size-fits-all solution. Sometimes simple is best.Sometimes detailed is better.

The key is understanding what you’re claiming and why. When it comes to tax, “easy” is great… but “correct” is even better.