InvoiceFlowby StackQuil

For freelancers, agencies & service businesses in India

From quotation to payment, all in one place.

Send GST-ready quotations, let clients approve them online, turn the accepted version into an invoice and track every payment — without spreadsheets or chasing PDFs on WhatsApp.

Start free

Demo needs no sign-up · Free plan needs no card

How it works

One workflow, start to finish

Most tools stop at the invoice. InvoiceFlow starts at the quotation — where service work actually begins.

  1. 01

    Quote

    Build a quotation from your saved services. GST, discounts and totals are worked out as you type.

  2. 02

    Share & approve

    Send one secure link. Your client reviews, comments and accepts — no login, no back-and-forth PDFs.

  3. 03

    Invoice

    Convert the accepted version into an invoice — or an advance plus a balance invoice — in one click.

  4. 04

    Get paid

    Record full or partial payments, issue receipts and see exactly who still owes what.

Product tour

See it the way your clients do

Real screens from the app, with sample data.

Pixel & Pine Studio (sample)

Quotation

QT-0118

From

Pixel & Pine Studio (sample)

Your address appears here

Delhi

Prepared for

Sample Client Pvt Ltd

Client address

Delhi

Quotation no.
QT-0118
Date
11 Oct 2026
Valid until
26 Oct 2026
Place of supply
Delhi (07)

Website redesign (sample)

#ItemHSN/SACQtyRateGSTAmount
1

Website design & development

8 responsive pages, CMS, contact forms.

9983141 job₹45,000.0018%₹45,000.00
2

Content writing

9983148 pages₹1,500.0018%₹12,000.00
3

Domain registration (pass-through)

—1 year₹999.00Non-GST₹999.00

Amount in words

Rupees Sixty Four Thousand Eight Hundred Forty Six and Five Paise Only

GST summary

RateTaxableCGSTSGST
18%₹54,150.00₹4,873.50₹4,873.50
Non-GST₹949.05₹0.00₹0.00
Subtotal
₹57,999.00
Discount (5%)
−₹2,899.95
Taxable value
₹55,099.05
CGST
₹4,873.50
SGST
₹4,873.50
Total
₹64,846.05

Notes

Thank you for your business.

Terms & conditions

50% advance, balance on delivery.

Try it now

The GST maths, done right

This is the same calculation engine the app uses — exact to the paisa, no floating-point surprises.

GST rate
Taxable value
₹50,000.00
CGST 9%
₹4,500.00
SGST 9%
₹4,500.00
Invoice total
₹59,000.00

Rupees Fifty Nine Thousand Only

Exact paise arithmetic, rounded half-up per line. A calculation aid only — confirm the right rate and treatment for your supply.

Features

Everything between “here's my quote” and “thanks, received”

GST worked out for you

CGST + SGST or IGST from your state and the place of supply. Mixed rates, exempt and zero-rated lines, tax-inclusive prices, HSN/SAC and a per-rate summary.

Client approval portal

Unguessable, expiring links you can revoke. Acceptance needs the client's name and an explicit confirmation — opening a link never counts as approval.

Versions you can trust

Sending freezes a version. Changes become a new revision, and the accepted version is kept exactly as agreed, with a full audit history.

Professional PDFs

Three A4 templates — Clean, Minimal and Agency — with your logo and brand colour, proper page breaks and amount in words.

Reports from real records

Received means money recorded, not invoices raised. Outstanding, overdue, aging, acceptance rate and monthly trends.

Due & overdue reminders

In-app alerts for due dates, expiring quotations, decisions and payments, plus ready-to-send WhatsApp/email reminder text.

CSV import & export

Bring clients over with a preview and duplicate check — nothing is overwritten. Export invoices, payments and quotations for your CA.

Teams & multiple businesses

Owner, admin and member roles, and separate workspaces for each business you run.

Pro

Built for how Indian service businesses get paid

Everything in Free, plus the tools that shorten the gap between “approved” and “received”.

UPI scan-to-pay

Every invoice PDF and client link carries a UPI QR for the exact balance — GPay, PhonePe, Paytm or any bank app.

Recurring invoices

Retainers and AMCs bill themselves: weekly to yearly, as drafts or issued automatically, never twice for the same date.

Client statements

One PDF with opening balance, every invoice and payment, and what's still due — ready for month-end follow-ups.

Quotation templates

Save your standard packages once and quote a new client in under a minute.

Payment insights

Average days to get paid, on-time rate and approval speed — from your real records, period over period.

All of this is switched on in the demo — try it free.

Client portal

Approvals that hold up later

Every decision records who accepted, which version, when, and their comment. If the quotation changes, the client sees the new version — and the old acceptance stays attached to the old one.

  • Mobile-friendly, no login for your client
  • Download PDF, accept, decline or ask a question
  • Links expire and can be revoked any time
  • Opening a link is never treated as acceptance

Quotation QT-0118 · sample

Restaurant website & SEO

Your response

Aman Verma
BackConfirm acceptance

Shown with your logo and brand colour on Pro

Pricing

Start free. Upgrade when it pays for itself.

Launch pricing in INR, billed monthly. Downgrading never deletes your data.

Free

For getting started

₹0 / month

  • 10 active clients
  • 10 quotations + invoices / month
  • GST calculations & PDF downloads
  • Manual payments, partial payments & receipts
Start free
Most popular

Pro

For freelancers & consultants

₹499 / month

  • 500 active clients
  • 200 quotations + invoices / month
  • GST calculations & PDF downloads
  • Manual payments, partial payments & receipts
  • Logo & brand colour on documents
  • All PDF templates
  • Client approval portal & share links
  • UPI scan-to-pay QR on invoices
  • Recurring invoices for retainers
  • Client account statements (PDF)
  • Reusable quotation templates
  • Due-date & overdue reminders
  • Advanced reports & trends
  • Payment & approval insights
  • CSV import & export
Start with Pro

Agency

For teams & studios

₹1,499 / month

  • Unlimited clients
  • Unlimited quotations & invoices
  • GST calculations & PDF downloads
  • Manual payments, partial payments & receipts
  • Logo & brand colour on documents
  • All PDF templates
  • Client approval portal & share links
  • UPI scan-to-pay QR on invoices
  • Recurring invoices for retainers
  • Client account statements (PDF)
  • Reusable quotation templates
  • Due-date & overdue reminders
  • Advanced reports & trends
  • Payment & approval insights
  • CSV import & export
  • Team members & roles
  • Up to 10 team members, 5 businesses
Start with Agency

Compare every feature →

FAQ

Straight answers

Is InvoiceFlow GST compliant?

InvoiceFlow calculates GST and prints the fields a GST tax invoice needs (GSTINs, place of supply, HSN/SAC, rate-wise CGST/SGST/IGST). It does not verify GSTINs, file returns or generate e-invoice IRNs, and it can't know your specific tax position — confirm rates and treatment with your CA.

Do my clients need an account?

No. They open a secure link, review the quotation, and accept or decline by typing their name and ticking a confirmation box. You can revoke a link at any time, and links expire automatically.

How does the UPI QR work?

On Pro, add your UPI ID in Settings. Invoices then carry a QR code (and an 'Open UPI app' button on phones) pre-filled with the balance due and invoice number. UPI apps don't report back to us, so you record the payment when it reaches your account — nothing is marked paid automatically.

Can clients pay online?

On Pro, every invoice carries a UPI scan-to-pay QR for the balance. There's no card or gateway checkout for your clients yet: you record payments you receive (UPI, bank transfer, cash, cheque — full or partial) and InvoiceFlow keeps balances and receipts. Nothing is marked paid because someone opened a link.

What happens if I downgrade?

Nothing is deleted. Your clients, quotations, invoices and payments stay readable and exportable. Only creating beyond the Free limits and paid-only features pause.

Can I fix an invoice after issuing it?

Issued invoices are locked so your records stay trustworthy. To correct one, cancel it (the number stays on record, marked cancelled) and issue a new invoice — duplicating takes one click.

Is the demo real?

Yes — 'Explore the demo' creates a private workspace with fictional sample data just for you. Everything works for real: PDFs, client approval, conversion and payments. It's deleted automatically after 24 hours.

See the whole flow in two minutes

Open a private demo workspace, accept a quotation as the client, convert it and record a payment. No sign-up.

Create free account