Best free apps to track expenses for UK side hustlers

Tracking business expenses does not need to cost anything when you are starting out. Several genuinely free mobile and web apps let UK side hustlers scan receipts, record mileage and create simple reports that make self assessment and basic bookkeeping far easier.

This guide looks at practical, no-cost options that suit bootstrapped founders and e-commerce sellers. Each tool is reviewed for receipt scanning, mileage tracking and HMRC compliance features, with clear steps to get started and examples of how they fit real side-hustle routines.

Why accurate expense tracking matters for UK side hustlers

Keeping clear records of what you spend helps you understand your real margins and cash flow. When it is time to complete your self assessment, having organised information reduces the chance of missing allowable expenses or spending hours hunting through bank statements.

HMRC expects records to be accurate and available if requested. Free tools can help you build this habit early without adding to your costs. Many side hustlers begin with a mix of personal and business spending, so separating them promptly avoids confusion later. Rules around allowable expenses change, so always check the latest GOV.UK guidance.

Receipt scanning in free tools

Receipt scanning turns paper or digital purchase proofs into searchable records. The best free options use your phone camera to capture the image, extract key details and store them securely.

Google Drive – Free with a Google account. Open the app, tap the camera icon, take a clear photo of the receipt, crop it and save in a dedicated business folder. Use the search function later by date or supplier name. Many side hustlers create a monthly folder structure inside Drive.
Microsoft Lens (formerly Office Lens) – Completely free. It straightens the image, improves contrast and lets you save directly as PDF or Word. Export to OneDrive or your phone gallery. Useful when you buy stock for an e-commerce side hustle and need to keep supplier invoices tidy.
Expensify – The free plan allows receipt scanning and basic categorisation. Snap a photo and the app attempts to read the total and date. Export reports as CSV for your own spreadsheets. The free tier limits the number of smart scans per month, so combine with manual entry for lower volumes.

Practical tip: Photograph receipts immediately after purchase while the details are fresh. Store both the image and a short note on what the purchase was for (for example, “packaging materials for online orders”).

Mileage tracking that meets HMRC expectations

Mileage is a common expense for side hustlers who deliver products, visit post offices or attend markets. HMRC accepts either actual vehicle costs or a standard mileage rate, but you must keep clear records of journeys.

Free tools that help:

Google Maps Timeline – Enable location history on your Android or iPhone. At the end of each month review the Timeline to see journeys made. Take screenshots or export data and note which trips were for business, adding the purpose and approximate miles. This is not automatic reporting but provides a verifiable log.
MileIQ – Offers a free trial period and limited free drives per month after. The app runs in the background, detects when you are driving and asks at the end of the trip whether it was business or personal. Review and categorise quickly. Export a summary report for your records. Check current limits on the MileIQ website as they change.
Simple spreadsheet plus phone GPS – Many bootstrapped founders use the free Google Sheets app. Create columns for date, purpose, start and end postcodes, miles and notes. Use Google Maps to calculate distance at the time of the trip. This method gives full control and is fully acceptable if kept consistently.

Example: A side hustler selling on Etsy drives to the post office three times a week. Logging each trip with date, purpose (“post parcels”) and miles takes less than 30 seconds and creates a clear audit trail.

Fully free or freemium bookkeeping apps suitable for bootstrapped founders

Several apps combine expense tracking, reporting and basic profit-and-loss views without charging for core functions.

Wave – Free accounting software aimed at small businesses and sole traders. Connect your bank feed (UK banks supported), categorise transactions and attach receipt photos. Generate reports that help when preparing self assessment. No monthly fee for the bookkeeping features, although payment processing carries a fee. Ideal for e-commerce sellers who want to see income and expenses in one place.
Google Sheets templates – Start with a free expense tracker template from the Google Sheets template gallery. Add tabs for mileage, receipts and monthly summaries. Use simple formulas to total columns. Many founders customise these with categories that match their e-commerce costs such as advertising, packaging and platform fees. Share the sheet with an accountant if needed.
FreeAgent – Offers a free version for sole traders with very low turnover. Includes expense tracking, mileage logs and tax-ready reports. Check the current eligibility criteria on the FreeAgent site because thresholds and terms change.

Choose based on volume. A side hustler with fewer than 50 transactions a month often finds a spreadsheet plus receipt photos sufficient. Higher volumes benefit from bank-feed automation in Wave.

Creating HMRC-compliant records with free tools

HMRC does not mandate any specific app but requires records that are complete, accurate and easy to understand. Combine the tools above into a simple workflow.

Take a photo of every receipt on the day of purchase using Google Drive or Microsoft Lens.
At the end of each journey, record mileage in a spreadsheet or approved app with date, purpose and distance.
Once a week, spend 15 minutes categorising transactions in Wave or your spreadsheet.
Keep digital records for at least six years. Store everything in one cloud folder that is backed up.
Export reports as PDF before your self assessment deadline to have a clear summary of expenses.

This routine helps side hustlers avoid the common mistake of claiming expenses without supporting records. It also makes it easier to spot patterns such as rising material costs that affect pricing decisions.

Putting it together – a weekly routine for side hustlers

A practical routine keeps everything current without taking much time.

Monday morning: review the previous week’s mileage and add any missed trips to your log.
After each purchase: photograph the receipt and save with a one-line description.
Friday afternoon: open Wave or your spreadsheet, categorise new transactions and check that bank feeds match receipts.
End of month: run a simple report showing total expenses by category. Compare against sales to understand your margins.

Over time this builds a clear picture of cash flow. For example, seeing that packaging costs form a notable share of revenue might prompt a switch to cheaper suppliers or adjusted product pricing. The discipline also prepares you if your side hustle grows and you need to register for VAT or incorporate.

When to consider paid upgrades or professional help

Free tools work well for early-stage side hustles. As transaction volume or complexity increases you may outgrow the free limits. Many apps offer straightforward paid plans that remove restrictions on scans or add automatic mileage calculations. Review the current pricing on each platform’s website before committing.

Loomworks in Liversedge supports selected early-stage founders with free desks, a registered address and mentoring, making it easier to focus on the business rather than overheads. For complex tax questions or when preparing incorporation documents, speak to an accountant or check the latest guidance on GOV.UK and Companies House. Free tools reduce cost but do not replace professional advice when your circumstances change.

Frequently asked questions

Are free receipt scanning apps accepted by HMRC?

Yes, provided the records are accurate, complete and kept for the required period. Photos of receipts stored in Google Drive or similar, combined with a clear description of the business purpose, are generally acceptable. Always keep the original digital image and note the date and what the expense was for.

Can I track car mileage for free and still meet HMRC rules?

You can. Using a spreadsheet to record date, journey purpose, start and end locations and calculated miles is a common free method. Apps that log drives automatically can also be used if you categorise business versus personal use. The key is consistency and retaining the records.

Is Wave really free for UK sole traders?

Wave provides its core bookkeeping, invoicing and expense tracking features at no monthly cost for sole traders and small businesses. Bank feeds for many UK accounts are included. Payment processing and some payroll features carry fees. Check the current terms on the Wave website as offerings can change.

How long should I keep expense records from side hustles?

HMRC generally expects records to be kept for six years from the end of the tax year. Digital copies are fine as long as they are clear and organised. Using cloud storage with good backup practices helps ensure records remain safe and accessible.

What is the best free way to organise expenses for self assessment?

A combination of receipt photos stored by month, a mileage log and a simple spreadsheet or Wave account works for most side hustlers. Spend a short time each week categorising so that when self assessment arrives you can quickly total each expense type and transfer the figures to your tax return.