Construction & trades
MTD software for air-conditioning and refrigeration engineers.
Keep systems running. Keep records up to date.
Installation projects and urgent service calls create a mixture of equipment invoices and small parts receipts. Avona helps independent air-conditioning and refrigeration engineers keep both under control.
- Who it is for
- Air-conditioning and refrigeration engineers working as sole traders, managing their own business records and MTD for Income Tax updates.
- Available now
- Digital records, bank feeds, statement imports, transaction categorisation and quarterly self-employment updates. Pro adds customer invoicing, VAT accounting and reporting.
- Monthly price
- From £15/month for Lite. Pro is £20/month.
- Free trial
- Full access for 7 days. No credit card required.
- Annual-return limitations
- Quarterly updates do not replace your annual tax return. HMRC lists annual-return items including PAYE income, interest, dividends and pensions as in development. Check the listing and confirm support for your income sources before relying on Avona for your annual return.
Making Tax Digital
It’s what comes in.
Before costs go out.
An installed system can represent a substantial customer payment before you pay the equipment supplier. Maintenance plans and repair callouts add further income streams to reconcile.
Understand Making Tax Digital →When does MTD apply?
Combined qualifying self-employment and property income, before expenses:
- Over £50,000 in 2024/25
- From 6 April 2026
- Over £30,000 in 2025/26
- From 6 April 2027
- Over £20,000 in 2026/27
- From 6 April 2028
Eligibility and exemptions matter. These are income thresholds, not tax-free allowances.
Check HMRC’s eligibility guidance ↗From the work to your records
Clear records for your refrigeration-system repair.
Bring the evidence into Avona, review the suggested categories and check the figures before submitting. These three examples show the records behind your refrigeration-system repair, shared purchases and a refrigeration-maintenance contract.
| What you bring | How you use Avona | What you check |
|---|---|---|
| £820 for your refrigeration-system repair £310 spent on replacement components and service supplies | Connect your bank or import the payment, then upload the invoice or receipt for replacement components and service supplies. Review the income and the purchase as separate records. | Keep £820 as the sale and the £310 cost separately. The £510 left after this cost is not turnover. Check that the spending is eligible for your business. |
| £100 mixed purchase £80 for parts for customer equipment; £20 for parts for your own appliance | Upload the itemised receipt and review the suggested category. Identify parts for customer equipment separately from parts for your own appliance. | Only the eligible £80 business portion belongs in business costs. Exclude the £20 personal purchase, and check that importing both the bank transaction and the receipt has not counted the spending twice. |
| £300 monthly service payment An agreement covering a defined service period | Bring the bank payment into Avona and retain the agreement for a refrigeration-maintenance contract. Check which month or service period the receipt covers. | Repeated descriptions can represent legitimate payments for different periods. Check the agreement before treating one as a duplicate, and keep one-off project fees or extra work separately identifiable. |
Keep supporting documents alongside your figures, review business use and apply your accounting method consistently. HMRC: keeping business records ↗
The costs behind your work
Six expenses worth
keeping records for.
Examples for air-conditioning and refrigeration engineers. Claim only eligible business costs; mixed use, equipment and your accounting method can change the treatment.
Replacement components
Refrigerant supplies
Leak-testing equipment
Calibration costs
Protective equipment
Business travel
One thing to watch
Separate equipment purchases from servicing costs
Buying a new diagnostic instrument is not the same transaction as paying to calibrate one. Keep detailed invoices so equipment and running costs can be reviewed using the right accounting treatment.
HMRC: office, property and equipment ↗Fit the admin around the work
A routine around your refrigeration-system repair.
Bring equipment invoices and service-call receipts together, then review customer payments across installations, repairs and maintenance.
Capture the supporting documents
Upload receipts or invoices for replacement components and service supplies. Keep the date, supplier and amount legible, and distinguish parts for customer equipment from parts for your own appliance.
How document capture works →Reconcile your refrigeration-system repair payments
Review each customer receipt against the work it covers. Keep the breakdown for a refrigeration-maintenance contract available alongside the bank entry, so fees, refunds or timing differences can be explained.
How bank review works →Review before you submit
Review Avona AI’s suggested categories, check that your refrigeration-system repair income is complete, and remove duplicate or personal spending. Keep the evidence for a refrigeration-maintenance contract ready for your annual-return review too.
Before you get started
Questions from air-conditioning and refrigeration engineers.
Does MTD apply to everyone in this profession?
No. This page covers air-conditioning and refrigeration engineers working as sole traders. Your start date depends on combined qualifying self-employment and property income before expenses, and any exemptions. Employment and limited-company work have different reporting arrangements.
How do I keep maintenance contracts separate from installation fees?
Retain each agreement and reconcile the regular service payments separately from one-off installations. This makes repeated payments understandable and helps identify missed receipts.
How do I record a refrigeration-maintenance contract?
Example: £300 monthly service payment (an agreement covering a defined service period). Repeated descriptions can represent legitimate payments for different periods. Check the agreement before treating one as a duplicate, and keep one-off project fees or extra work separately identifiable.
Which bookkeeping issue should I watch for?
Separate equipment purchases from servicing costs. Buying a new diagnostic instrument is not the same transaction as paying to calibrate one. Keep detailed invoices so equipment and running costs can be reviewed using the right accounting treatment.
Can I keep using my existing spreadsheet?
Yes. Bring your refrigeration-system repair income records and evidence of replacement components and service supplies into Avona using supported spreadsheet uploads. Check dates, categories, personal spending and duplicates against the original documents before you approve the records.
Do quarterly updates complete my annual tax return?
No. You still need the annual tax return and any relevant adjustments or other income. HMRC currently lists annual-return items including PAYE income, interest, dividends and pensions as in development for Avona. Confirm support for your own income sources and circumstances before relying on Avona for the annual return.
Built for the way you earn
Take the heat out of your service paperwork.
Choosing Avona
Your questions, answered.
Can I create customer invoices?
Yes. You can create customer invoices with Avona Pro.
What if I am VAT-registered?
Full VAT accounting is available with Avona Pro, so you can manage your VAT-registered business with Avona.
Can my accountant review my records?
Yes. You can connect your Avona account to your bookkeeper or accountant so they can review your records.
Can I use my phone on site?
Yes. Every feature has a mobile-friendly version, so you can manage your accounts from your phone while you are on the move.
Can I keep using my personal bank account?
Yes. Avona supports Open Banking connections and PDF bank statement uploads. You can clearly separate personal and business transactions to keep your business records organised.