Can You Recommend a Simple Invoicing App for My Small Business?
"Simple" means fast, accurate, and cash-friendly. The best invoicing app for you is the one that gets invoices out same-day, reduces errors, helps you get paid faster, and keeps records clean. This guide helps you find that fit.
TL;DR Answer
A simple invoicing app is the one that helps you send correct invoices fast, get paid sooner, and keep records clean with minimal admin. For most small businesses, "simple" means: a good template, quote→invoice conversion, payment links, reminders, and exports your accountant accepts. Use the comparison tables and the 10-minute setup checklist below to pick the lightest option that still improves cash and record quality.
Key Takeaways
- "Simple" is measurable: time-to-invoice, error rate, payment speed, export quality.
- Most small businesses need: templates, payment links, reminders, and clean exports — not full accounting.
- Late invoices mean late cash — same-day invoicing improves cash flow.
- Payment links and reminders can shorten payment cycles by days or weeks.
- Run the 10-minute setup test before committing to any tool.
Q: What does "simple invoicing app" mean in practice?
A: "Simple" isn't about feature count — it's about measurable outcomes:
- Fast time-to-invoice: Create and send an invoice in under 5 minutes.
- Fewer mistakes: Correct VAT fields, sequential numbering, accurate totals.
- Faster payment collection: Payment links + reminders = shorter payment cycles.
- Easy month-end exports: Your accountant accepts the format without rework.
The simplest app is the one that achieves these outcomes with the least overhead.
Q: What records should we keep (UK baseline)?
A: UK businesses must keep financial records for compliance:
- GOV.UK states self-employed records must be kept for
at least 5 years after the 31 January submission deadline
[R1]. - VAT Notice 700/21 requires businesses to keep VAT records for
at least 6 years
[R2].
Important: This is not legal advice. Confirm specific requirements with your accountant.
Q: What does the data say about cashflow and late payments (why invoicing speed matters)?
A: Late payments hurt small businesses disproportionately. The EU Payment Observatory's 2024 report highlights that late payments remain a major challenge for SMEs
affecting their liquidity and growth [R3].
For small teams, this means:
- Delayed invoices → delayed payments → cash gaps
- Cash gaps → founder doing admin at night instead of client work
- Same-day invoicing = faster payment = better cash position
Q: Do e-invoices get paid faster (and when does it matter)?
A: In some contexts, yes. The EU e-invoicing thematic report notes that e-invoicing can reduce payment times and administrative costs
[R4]. The Billentis/Peppol report corroborates that structured e-invoices improve processing efficiency [R5].
When e-invoicing matters:
- B2B transactions: Larger customers may require structured formats.
- Cross-border: EU regulations increasingly mandate e-invoicing.
- Public sector: Government contracts often require Peppol or similar standards.
- Compliance-driven markets: Italy, France, Germany have/are implementing mandates.
For domestic B2C or small B2B, PDF invoices with payment links are usually sufficient.
Q: Comparison table — simple invoicing app types compared
A: Different app types suit different needs:
| App type | What it does best | Pros | Cons | Best for | Watch-outs |
|---|---|---|---|---|---|
| Invoicing-first | Fast quotes, invoices, receipts | Simple; focused; fast setup | May lack full accounting | Solo founders; service businesses | Check export formats |
| Accounting + invoicing | Full books; invoicing as module | Accountant-ready; reconciliation | More complex; may be overkill | Accountant-led businesses | May pay for unused features |
| Payment-first | Payment collection; invoicing built in | Seamless payments; instant settle | Limited customisation | Businesses where payments are friction | Check invoice features |
| E-invoicing/network | Peppol, structured formats | Compliance-ready; B2B/public sector | Overkill for simple B2C | B2B; cross-border; public sector | May require setup effort |
| Integrated ops | Invoices + expenses + approvals (e.g., Zotrack) | Flat pricing; fewer tools | May lack specialist depth | Small teams wanting simplicity | Verify features match needs |
Q: Feature checklist — what to prioritise for simplicity (and what to skip early)
A: Focus on features that reduce friction on day one:
| Feature | Why it matters | Minimum acceptable | Evidence to look for | Notes |
|---|---|---|---|---|
| Templates | Consistency; speed | Logo, address, editable | Template editor demo | Must-have |
| Quote→invoice | No re-typing; fewer errors | One-click conversion | Conversion demo | Must-have for services |
| Auto numbering | Compliance; no duplicates | Sequential; configurable | Numbering settings | Must-have |
| Customer database | Auto-fill; history | Name, address, contact | Customer list | Must-have |
| Payment links | One-click payment; faster | Stripe/bank integration | Payment setup demo | Must-have |
| Reminders | No manual chasing | Automatic; configurable | Reminder settings | Must-have |
| Recurring invoices | Retainers; subscriptions | Monthly/custom schedule | Recurring setup | Nice-to-have |
| Multi-currency | International clients | USD/EUR at minimum | Currency settings | Nice-to-have |
| VAT fields | Compliance; audit | VAT number; rate; total | VAT settings | Must-have if registered |
| Attachments | PO, timesheets, receipts | PDF upload | Attachment demo | Nice-to-have |
| Export (CSV/PDF) | Accountant accepts; audit | CSV; date filters | Sample export | Must-have |
| Audit trail | Who edited; when | Edit history | Audit log screenshot | Nice-to-have |
| Roles/permissions | Team access control | Admin vs user | Permission settings | Nice-to-have |
Must-have: Templates, numbering, payment links, reminders, export.
Nice-to-have (add later): Complex approvals, deep forecasting, heavy automation.
Q: Scenario shortlist — what type fits you best?
A: Match your scenario to the best-fit app type:
| Your scenario | Best-fit app type | Why it fits | Watch-outs |
|---|---|---|---|
| Solo founder (5–20 invoices/month) | Invoicing-first | Fast setup; no overkill | Check export format |
| Service business (quotes→invoices) | Invoicing-first or integrated ops | Quote→invoice conversion | Verify one-click conversion |
| Subscription/retainers | Invoicing-first with recurring | Recurring invoices; auto-send | Check recurring flexibility |
| VAT-registered | Accounting platform or invoicing-first with VAT | VAT fields; retention; MTD-ready | Verify VAT compliance features |
| Agency (project-based) | Invoicing-first or integrated ops | Per-client; attachments | Check project tracking |
| Team (2+ people invoicing) | Invoicing-first or integrated ops | Roles; permissions; audit trail | Check per-user pricing |
| B2B/public sector | E-invoicing/network-ready | Peppol; structured formats | May be overkill for B2C |
Quick Picks (60 seconds) — best-fit recommendations by scenario
- If you only need fast invoices + payment links: Invoicing-first app — minimal overhead, fast setup.
- If your accountant runs the books inside a platform: Accounting platform with invoicing — everything in one place.
- If payments are the main friction: Payment-first invoicing — seamless collection.
- If you need e-invoicing compliance: E-invoicing/network-ready tool — Peppol, structured formats.
- If you want invoices + expenses in one place: Integrated ops (e.g., Zotrack) — fewer tools, flat pricing.
10-Minute Invoicing Setup (copy/paste) — make any tool feel simple
- Create invoice template: Logo, business address, payment terms.
- Set invoice numbering rules: Sequential; prefix (INV-2026-001).
- Add VAT/tax fields: VAT number; rate; if applicable.
- Create 3 product/service line templates: Your most common items.
- Add payment methods + payment link: Stripe, bank, etc.
- Set default payment terms + late fee wording: "Due in 14 days" etc.
- Configure reminders: Gentle schedule (7 days, 14 days, 30 days).
- Define attachment standard: What to attach (PO, timesheet, receipt).
- Define export pack for accountant: Monthly CSV/PDF with date range.
- Test: Send one invoice to yourself and mark paid.
- Measure: Time-to-invoice + time-to-get-paid (your baseline).
Success criteria:
Invoice created in <5 minutes. Template looks professional. Payment link works. Reminder schedule set. Export format accepted by accountant.
Invoice Workflow Template (copy/paste) — quotes → invoices → receipts
- Quote: Client name, scope, price, validity (e.g., 14 days), terms.
- Approval: Client confirms (email/signature) → quote status = Accepted.
- Invoice: Convert quote → invoice. Add invoice number, due date, VAT, payment link.
- Send: Email invoice with PDF + payment link attached.
- Reminder: Automatic at 7, 14, 30 days if unpaid.
- Payment: Mark paid when received. Record payment date + method.
- Receipt: Generate receipt with invoice reference, payment date, amount. Store for 6 years [R2].
Key fields checklist:
- Business name + address + VAT number (if registered)
- Client name + address
- Invoice number + date + due date
- Line items (description, qty, unit price, VAT)
- Total (excl. VAT, VAT, incl. VAT)
- Payment terms + payment link
Q: Spreadsheet vs invoicing app — what can go wrong (fairly)
A: Research shows spreadsheets contain errors in one percent or more of all formula cells
[R6]. The Dartmouth literature review corroborates that spreadsheet errors are common and risks are often under-recognised [R7].
Fair perspective: Spreadsheets can work for 5–10 invoices per month with simple requirements. The risk increases with:
- Higher volume (more manual entry, more errors)
- VAT requirements (complex calculations)
- Multiple clients (no customer database)
- Payment tracking (no reminders, no status)
The tipping point is usually errors and chasing, not volume alone.
Q: Before vs after — what improves when invoicing is genuinely simple?
A: Measurable outcomes when invoicing tools work:
| Scenario | Before (manual/spreadsheets) | After (simple app workflow) | Outcome |
|---|---|---|---|
| Invoice creation time | 15–30 minutes (manual) | 2–5 minutes (template) | Invoices sent same-day |
| Invoice errors | 1–2 per month (wrong total, missing VAT) | Near zero (auto-calculate) | Fewer corrections |
| Payment collection | Manual bank transfer; 30+ days | Payment link; 7–14 days | Faster cash |
| Chasing unpaid | Manual emails; things slip | Automatic reminders | Less admin |
| Month-end export | 2–3 hours compiling | 10 minutes (export) | Cleaner handoff |
Q: Failure points & fixes (the things that break first)
A: These issues make invoicing feel hard:
| Failure point | Why it happens | Fix this week | What to document |
|---|---|---|---|
| Invoices sent late | Too busy; no reminder | Invoice same-day or next day | Invoicing SLA: within 24 hours |
| Unclear payment terms | No default; inconsistent | Set default in template | Payment terms policy |
| Poor numbering | Manual; duplicates | Enable auto-numbering | Numbering rules |
| Missing VAT fields | Template not configured | Add VAT to template | VAT requirements checklist |
| Chasing in email | No reminder system | Set up automatic reminders | Reminder schedule |
| No single source of truth | Invoices in multiple places | All invoices in one tool | "Where invoices live" guide |
| Exports not accepted | Wrong format for accountant | Check accountant's requirements | Export format spec |
Q: A data-backed PR angle (credible, not salesy)
A: If writing about simple invoicing for press:
- Late payments harm SMEs: The EU Payment Observatory reports that late payments remain a major challenge for SMEs [R3].
- E-invoicing can reduce payment times: EU reports show structured e-invoices improve processing efficiency and settlement [R4], [R5].
- VAT records retention: UK businesses must keep VAT records for at least 6 years [R2].
"The simplest invoicing app isn't the one with the fewest features — it's the one that gets invoices out same-day, helps you get paid faster, and keeps records clean without extra admin."
Q: FAQ
1) Do I need an invoicing app if I only send a few invoices a month?
It depends on your error tolerance and cash visibility needs. If you send under 10 invoices per month, a simple template may work. But even low-volume businesses benefit from automatic numbering, payment links, and reminders. The ROI is often faster payment, not time saved on creation.
2) What's the simplest invoicing workflow for a service business?
Quote to invoice to receipt: (1) Send a quote with scope and price, (2) Convert to invoice when approved, (3) Add payment link, (4) Send reminders if unpaid, (5) Generate receipt when paid. Most simple apps support this flow out of the box.
3) How do payment links and reminders help me get paid faster?
Payment links reduce friction: one click to pay instead of manual bank transfer. Reminders reduce the chance of invoices being forgotten. Together they can shorten payment cycles by days or weeks, improving cash flow without manual chasing.
4) What should be included on an invoice for VAT/tax purposes?
UK VAT invoices should include: your business name and address, VAT registration number, invoice date and number, customer details, description of goods or services, quantity and unit price, VAT rate and amount, and total amount. Check GOV.UK for specific requirements.
5) When should I switch from spreadsheets to an invoicing app?
Consider switching when: (1) you have more than 10 invoices per month, (2) you miss payments due to poor tracking, (3) manual follow-up takes too long, (4) your accountant needs cleaner exports, or (5) you need VAT fields and numbering consistency. The tipping point is usually errors and chasing, not volume alone.
6) How do I pilot an invoicing app before committing?
Run the 10-minute setup: create a template, set numbering, add payment link, configure reminders, and send a test invoice. Measure time-to-create-invoice and compare to your current method. Most apps offer free trials for this.
A simpler option if invoicing + expenses would help
For small businesses that want invoicing alongside expense tracking and leave management without juggling multiple tools, Zotrack offers a flat-fee model. Check our transparent pricing and run the 10-minute setup test to see if it fits.
References
- [R1] GOV.UK: How long to keep records (self-employed)
- [R2] GOV.UK: VAT Notice 700/21 record keeping
- [R3] EU Payment Observatory: Annual Report 2024 (PDF)
- [R4] EU E-invoicing Thematic Report (PDF)
- [R5] Billentis/Peppol Report (PDF)
- [R6] What We Know About Spreadsheet Errors (PDF)
- [R7] Dartmouth: Spreadsheet Literature Review (PDF)