10 Best AI Tools for Writing Quotes, Invoices and Business Proposals
These three documents are usually lumped together as “paperwork”, which is exactly why so many small businesses do them badly. A quote is a sales document. A proposal is a sales document. An invoice is a cash-flow instrument. None of them is admin, and treating them as admin costs money at both ends — work you don’t win, and money you don’t collect.
AI genuinely helps with all three, and most of what you need is free. But the biggest win on this page isn’t a tool at all: it’s knowing that UK law already gives you the right to charge interest on late payments automatically, without any clause in your contract.
That’s in the callout below, with the current rate. Read it before the tool list — it’s worth more than any subscription here.
What each tool helps with
| Win the work | ChatGPT, Claude, Gamma, Canva |
| Send & get paid | QuickBooks, Xero, FreeAgent, free options |
| Chase what’s owed | Automated reminders, Claude |
You can also claim fixed compensation on top — £40 for a debt up to £999.99, £70 for £1,000 to £9,999.99, and £100 for £10,000 or more, per overdue invoice. And you have six years to claim it.
Why this matters: Office of the Small Business Commissioner research found businesses spend an average of 86 hours a year chasing late payments, and 38 businesses close every day because of overdue invoices. A Small Business Protections Bill introduced in May 2026 proposes a 60-day payment cap for large businesses, mandatory statutory interest and enforcement powers for the Small Business Commissioner, expected to come into force in 2027 if passed.
These are B2B rights only — different rules apply to consumers — and the base rate moves, so check the current figure before claiming. But if you’re owed money, this is real leverage most suppliers never use.
Win the workQuotes and proposals are sales documents
ChatGPT
Quotes & covering notes
ChatGPT writes the parts of a quote that actually sell it: the covering note explaining what’s included and why, the scope description that prevents arguments later, and the follow-up email three days after you sent it.
That follow-up is the highest-return use here. Most quotes that go quiet aren’t rejections — they’re forgotten, and a short, friendly nudge converts a meaningful share of them. Having it drafted in ten seconds removes the reluctance that stops most people sending it at all.
Claude
Proposals & terms
Claude is the better tool when the document is long and the stakes are real — a full proposal for a tender or a substantial contract, your terms and conditions, or a scope of work that needs to be unambiguous.
It’s also useful in the other direction: paste in a client’s contract or a tender document and ask what you’re actually committing to. Payment terms, liability, change control and termination clauses are where small businesses get caught, and reading them properly is worth an hour.
Gamma
Proposal decks
Gamma turns notes into a designed proposal in about a minute, which changes the economics of pitching. For work above a certain value, a proper document beats an email with a number in it — and Gamma makes producing one cheap enough to do every time.
Its view-tracking is quietly useful in a sales context: knowing whether a prospect opened your proposal, and how far they read, tells you whether to chase and what to lead with when you do.
Canva
Branded templates
Canva is where you build the quote and proposal templates you’ll reuse for years — your branding, your standard sections, your terms, your price presentation — so every document that leaves your business looks like it came from the same place.
The presentational difference matters more at the small end of the market than people expect. When a customer is choosing between three quotes of similar value, the one that looks considered often wins on perceived competence alone.
Send & get paidInvoicing that chases for you
QuickBooks
Invoicing with automated chasing
QuickBooks with Intuit Assist creates and sends invoices, tracks what’s outstanding, and — the feature that matters — automatically chases unpaid ones on a schedule you set, without you having to decide each time whether to send an awkward email.
Automated reminders are the single most effective intervention on late payment, precisely because they’re impersonal and consistent. With Making Tax Digital extending to more sole traders, you likely need compatible software anyway.
Xero
The main alternative
Xero covers the same ground with a different interface and an unusually deep app marketplace, plus unlimited users on every plan — which matters if more than one person raises invoices or your accountant wants direct access.
Between the two, most people should choose on which their accountant prefers and which integrates with the other systems they run. The invoicing and chasing capabilities are broadly comparable, and switching later is genuinely painful.
FreeAgent
Built for UK sole traders
FreeAgent is UK-built and aimed squarely at freelancers, contractors and small limited companies — time tracking that flows into invoices, expense capture, self assessment and corporation tax estimates, and MTD-compatible filing.
Its notable feature is that it’s free for customers of certain UK business bank accounts, which for a sole trader can mean proper accounting software at no additional cost. Worth checking whether your bank includes it before paying for anything.
Free invoicing tools
When you’re just starting
If you’re issuing a handful of invoices a month and don’t yet need accounting software, free tools like Zoho Invoice and Wave handle creation, sending, payment links and automatic reminders without a subscription.
The honest advice: start here rather than paying for capability you don’t use. Move to full accounting software when tax becomes real work, when you need MTD compatibility, or when tracking what’s owed across dozens of invoices stops fitting in your head.
Chase what’s owedThe part everyone avoids
Automated payment reminders
A feature, not a product
Every tool above includes scheduled reminders, and switching them on is the highest-return five minutes in this entire guide. A sensible sequence: a polite note three days before due, one on the due date, then at seven, fourteen and thirty days overdue, each firmer than the last.
The reason automation works is that it removes the emotional decision. Most small business owners delay chasing because it feels confrontational and they don’t want to damage the relationship — so the reminder that goes out automatically at 9am on day seven does the job the owner keeps postponing.
Claude, for the difficult letters
Escalation without burning bridges
When reminders stop working, Claude helps you write the next stage properly: a firm but professional letter setting out the amount owed, the statutory interest accruing and the fixed compensation claimable, with a clear deadline before further action.
Referencing your statutory rights specifically tends to move things, because it signals you know the position rather than merely being annoyed. Use it to draft and understand; take proper advice before issuing formal proceedings, and check the current base rate when you calculate the interest.
What to actually do this week
Switch on automated reminders in whatever invoicing tool you already use. It takes five minutes, costs nothing, and addresses the problem that closes businesses. If you don’t have a tool, start with a free one rather than researching for a fortnight.
Then build your templates once. A branded quote template in Canva, a standard scope-and-terms document drafted with Claude, and a saved ChatGPT prompt for quote covering notes and follow-ups. After that, sending a professional quote takes minutes rather than being a small project you postpone.
And add two lines to every invoice: your payment terms, and a note that statutory interest and compensation may be charged on late payment under the 1998 Act. You have those rights whether or not you mention them — but mentioning them changes behaviour, and it costs nothing. Check whether a prospective client appears on public payment-practice reporting before taking on large work; persistent late payers are a matter of record.
Frequently asked questions
Can I really charge interest without it being in my contract?
For business-to-business debts in the UK, yes. The Late Payment of Commercial Debts (Interest) Act 1998 gives suppliers an automatic statutory right to interest at the Bank of England base rate plus eight percentage points, and you don’t need a contract clause or prior notice for it to start accruing from the day after payment falls due. As of June 2026 that meant 11.75% a year, though the base rate moves so check the current figure. On top of that you can claim fixed compensation for recovery costs — £40, £70 or £100 depending on the size of the debt, once per overdue invoice — and you have six years to make a claim. Two important limits: these are B2B rights only, so chasing a consumer works differently and generally needs contractual terms; and you can set your own contractual rate instead if you prefer, but it must be reasonable, since courts can strike down rates they consider punitive. Around 8–15% is generally accepted.
Should I actually charge it, or will I lose the client?
That’s a commercial judgement, and the honest answer is that you often don’t need to charge it to benefit from it. Simply stating on your invoice that statutory interest and compensation may be applied changes payment behaviour, because it signals that you track this and know your position. Many suppliers use the right as leverage in a conversation rather than actually invoicing for it — “as it stands I’d be entitled to claim £X in interest and £70 compensation, but I’d rather just get the invoice settled this week” is a considerably stronger position than another polite reminder. Where you should charge it without hesitation is with clients who are persistently late, who’ve ignored several reminders, or who you’re prepared to lose. And be clear-eyed: a client who reliably pays 60 days late is financing their business with your money, which has a real cost to you. Sometimes losing them is the right outcome.
What makes a quote actually win the work?
Rarely the lowest number, which is the mistake most small businesses make. Three things move the needle more. First, speed — a quote sent within a day while the customer is still thinking about the problem beats a better one sent a week later. Second, clarity about scope: saying precisely what’s included and, just as importantly, what isn’t, prevents the disputes that destroy margin later and signals that you’ve done this before. Third, presentation — when several quotes are close on price, the one that looks professional wins on perceived competence, and that’s a template you build once. Two additions worth making: offer options rather than a single price, because a good-better-best structure lets a customer choose up rather than deciding yes or no, and always follow up. Most quotes that go silent were forgotten rather than rejected, and a short nudge after three days recovers a meaningful proportion of them.
Can AI write my terms and conditions?
It can produce a solid first draft that you then have checked, and that’s a reasonable use — but don’t treat the output as a finished legal document. AI is genuinely good at structuring the standard sections, explaining what a clause does in plain English, and helping you understand a client’s contract before you sign it. What it can’t do is know your jurisdiction’s current consumer law, your sector’s specific requirements, or whether a limitation of liability clause would actually be enforceable. For low-value straightforward work, a well-drafted AI first draft reviewed by you is probably proportionate. For anything substantial — significant contract values, subcontracting, anything involving consumers, or work where a dispute could seriously hurt you — pay a solicitor to review it once. That review costs a fraction of a dispute, and a good set of terms is an asset you’ll reuse for years across every job you quote.
The bottom line
Quotes and proposals win work; invoices collect the money — and neither is admin. Build your templates once so a professional quote takes minutes, follow up every quote that goes quiet, and switch on automated payment reminders today because they remove the emotional decision that stops most owners chasing. Then use the leverage the law already gives you: statutory interest and fixed compensation apply automatically to late B2B payments in the UK, with no contract clause required. You don’t have to charge it to benefit from knowing it — but you should certainly stop letting clients finance their businesses with your cash flow.
Pricing is accurate to the best of our research at the time of writing and is set by each provider — always check current pricing before subscribing. Late payment information reflects publicly reported positions at the time of writing and applies to UK business-to-business transactions; the Bank of England base rate moves, so verify the current statutory interest rate on GOV.UK before making a claim, and note that proposed legislative changes may alter the position. Nothing here is legal, tax or financial advice — take proper advice on contracts, terms and debt recovery.