Software contractor
invoice template

Software contractors invoice end clients or recruitment agencies for development work on day-rate contracts, usually monthly against an approved timesheet. Below is a ready-made software contractor invoice template, with worked example lines, the VAT and payment rules that apply, and the mistakes that most often delay payment.

What goes on a software contractor invoice

Show the contract or purchase order reference, the period, the days worked with dates, the day rate, and any approved expenses. Attach or reference the approved timesheet.

Line by line: Software development, contract ref on invoice, 20 days × £550.00 = £11,000.00; Approved travel to client site, 1 × £140.00 = £140.00. The subtotal is £11,140.00. The example assumes you are not VAT registered, so there is no VAT and the total due is £11,140.00. The figures are illustrative, not a price guide, so use your own rates.

The legal minimum is the same for every trade. GOV.UK says an invoice needs a unique number, your business name and address, the customer's name and address, a description of the work, the supply date and invoice date, the amount charged, VAT if you charge it, and the total due. This template lays each of those out for software contractors; for the detail, read what a UK invoice must include.

Give each invoice the next number in a single sequence and never reuse one. A cancelled invoice keeps its number and is cancelled with a credit note. If you want a format that stays tidy for years, try the invoice number generator.

How software contractors price their work

Contracts are priced by the day, set by the market for the skill set, with half days and overtime defined in the contract. Expenses are payable only when the contract allows them.

Keep the pricing visible. Each line should show the quantity, the unit and the rate, so the customer can match it to the quote. To set rates that cover your costs and your tax, try the day rate calculator; for materials and stock you resell, the profit margin calculator shows the margin you really make.

Agree this before you start

Agree the day rate, what counts as a day, notice periods, the timesheet approval process, expenses, and who you invoice: the end client or the agency. Look closely at how the work is actually done, because working like an employee affects your employment status.

When to send a software contractor invoice

Monthly, or at the end of each timesheet period, once the timesheet is approved.

An invoice sent on the day tends to be paid on time; one sent weeks later tends to be paid weeks later. Email it as a PDF and keep a copy. The invoice due date calculator shows exactly when payment falls due under your terms.

VAT on software contractor invoices

Development services are standard-rated for a registered contractor. Most full-time contractors pass the £90,000 threshold within a year, so plan for registration.

Once registered, software contractors charge 20% to UK clients. For overseas business clients the service is normally supplied where the customer belongs, so no UK VAT is charged; say so on the invoice and keep evidence that the customer is in business, such as their VAT number or company details.

Registration is compulsory once taxable turnover in the last 12 months passes £90,000, or when you expect to pass it within the next 30 days. Check your position with the VAT registration checker; until then, see invoicing without a VAT number.

Who software contractors invoice

Business clients pay through accounts payable, not the person you work with. Get the purchase order, the invoicing email and the payment terms agreed before the first sprint or deliverable, and quote them on every invoice. When a business pays late, the Late Payment of Commercial Debts (Interest) Act gives you interest at 8% above Bank Rate plus fixed compensation.

Agencies often self-bill contractors, generating the invoice from your approved timesheet. If they do, keep the self-billing agreement and check each self-billed invoice rather than raising your own. Operating through your own limited company brings the off-payroll working rules into play; as a sole trader, HMRC looks at whether you are genuinely self-employed.

Recharging costs and expenses

When you agreed to pass on costs, list them separately: mileage at an agreed rate, parking, materials or anything bought for the customer. The recharge is income and the cost is an expense, both in full. Registered businesses charge VAT on the recharge as part of their service; a true disbursement, paid as the customer's agent, is the narrow exception. Use the mileage calculator to value your business miles.

Timesheets, milestones and scope changes

Evidence gets digital invoices paid: a timesheet for time-based work, a milestone sign-off for fixed-price work, and an approved change request for anything outside scope. Invoice changes on their own lines with the approval reference. Contractors should also know where they stand on employment status: a sole trader invoicing clients in their own business name, with their own terms and several clients, looks like a business; a single client directing your hours looks like employment.

Deposits, stages and cancellations

Not applicable to day-rate contracts.

Invoice time-and-materials work in arrears, usually weekly or monthly, with the days worked listed. Invoice fixed-price work by milestone, with a deposit to start. Retainers are billed in advance each month for the hours or outcomes they cover.

Payment terms for software contractors

Agencies commonly pay 7 to 30 days after timesheet approval.

Between businesses, the default when nothing is agreed is 30 days from receipt of the invoice or the work, whichever comes later, and agreed terms should not normally exceed 60 days. Late business payers owe statutory interest at 8% above Bank Rate plus fixed compensation per invoice; the late payment interest calculator does the sums. Private individuals are not covered by that Act, so agree your terms with them in writing before the work starts.

Getting paid faster

Put everything the customer needs to pay on the invoice: your bank name, account name, sort code and account number, and the reference to use, normally the invoice number. Give a due date, not just "on receipt". Then follow a routine: a reminder the day after the due date, another a week later, and a firmer letter after two weeks. Most late payment is disorganisation, not refusal, and a routine fixes it. Invoice payment terms compares the common options, and the due date calculator turns them into a date.

If a customer disputes the invoice

When a customer queries an invoice, reply quickly and in writing, quote the quote or agreement, and ask them to pay the part they accept while you resolve the rest. A credit note can settle a partial dispute cleanly. Unpaid after reminders? Send a letter before action with a final date; in England and Wales, claims up to £10,000 can then go to the small claims track. Invoice disputes and small claims for an unpaid invoice have the detail.

Common software contractor invoicing mistakes

• Invoicing before the timesheet is approved. Agencies pay against approved timesheets; submit the timesheet first so the invoice is not rejected.
• Invoicing work the agency already self-billed. If the agency self-bills, do not raise a second invoice; reconcile its statement to your timesheets.
• Ignoring employment status. Working full time for one client, under their control, on their equipment, looks like employment; keep evidence of how you work as a business.
• Leaving out the due date. "Payment due within 14 days" or a date on the invoice gives you something to chase against. Without one, business customers default to 30 days.
• Losing track of what is unpaid. Chase on the day after the due date, not a month later; the guide to chasing an unpaid invoice has the wording.

Checklist before you send it

A quick check before sending saves a chase later:

• The invoice number is the next in your sequence and has never been used.
• The customer's name and address are right, with their purchase order or reference if they use one.
• Each line shows what was done, the quantity, the unit and the rate.
• The subtotal and total add up, and VAT appears only if you are VAT registered.
• The invoice date, a due date and your bank details are on it.
• A copy is saved with your records before you press send.

Keep a copy of every invoice

Your invoices are the evidence behind the income on your tax return, so keep a copy of every one. Making Tax Digital for Income Tax makes that digital: from 6 April 2026 for qualifying income over £50,000, from April 2027 over £30,000, and from April 2028 over £20,000, with quarterly updates to HMRC. Check your start date with the MTD requirement checker.

Download the software contractor invoice template

Download it as a Word document for Word or Google Docs, as an Excel workbook whose totals are live formulas, or as a print-ready PDF. Prefer to fill it in on screen? The free invoice generator opens pre-filled with the example software contractor lines, lets you choose a template and colour, and makes a finished PDF in a minute, with nothing stored.

For the tax side of the trade, from allowable expenses to Making Tax Digital, read the self-employed software contractor tax guide. A TapTax account, free to start, keeps your invoices and records together and files your quarterly updates to HMRC.