Invoicing

Send the invoice.
Get paid on it.

Name: app.kevinchia.sg Invoicing
Price: 365 SGD

A branded invoice with a PayNow QR for exactly what is owed, sent by email or WhatsApp. Reminders chase late payers, and a paid invoice posts itself to your P&L.

Built for small businesses in Singapore. Unlimited invoices, as part of Pro 365.1

Kopi Design Studio · INV-0012

Amount due S$2,180.00 Due 10 Sep 2026

Scan with any banking app. The amount is set for you.

I have paid

Download PDFTax Invoice

What your customer opens. The QR asks for S$2,180.00, and they cannot change it.2

Write it once.
The rest follows it.

Write it

Pick the customer, add the lines or tap the things you bill for often, set a due date. GST is worked out for you, line by line.

Send it

By email, by WhatsApp, or as a link. You see the moment they open it.

They pay by PayNow

They scan the QR and the amount is already there. When they tap “I have paid”, you get a Telegram with a button to record it.

It lands in your P&L

An issued invoice posts its revenue and its GST into the month it is dated, on its own. Nothing is typed twice.

What happens to
one invoice.

INV-0012 · Tan Wei MingPaid

Brand design, 3 conceptsS$2,000.00

GST (9%), code SRS$180.00

Sent03 Sep, email + WhatsApp

Opened03 Sep, 9.14pm

Reminder emailed09 Sep, by itself

Paid by PayNow10 Sep

Posted to your P&LSeptember

TotalS$2,180.00

The QR asked for S$2,180.00, to the cent. Your customer could not type a smaller number. On an invoice split into a deposit and the rest, it asks for the part that is due now.

Nobody had to remember to chase it. You saw it opened the same night, and one polite reminder went the day before it was due. Once it was paid, the reminders stopped.

Recording the payment did the accounting. S$2,000.00 of revenue and S$180.00 of output tax went into September, stamped standard-rated, ready for your GST F5.4

How we compare

app.kevinchia.sg vs a Word or Excel invoice

Most small businesses start with a template and a screenshot of their PayNow QR pasted underneath. It works. Then the invoices go out, and the part a template cannot do begins.5

app.kevinchia.sg

A template

PayNow QR on the invoice

Yes, with the amount locked

A screenshot, and they type the amount

Invoice numbers

Given out in order, no gaps

You keep count

Know when they opened it

Yes

Chasing a late payer

Email reminders on the days you choose

You message them yourself

Who owes you, and how late

On one screen

In your head, or a second sheet

Paid money in your accounts

Posts itself

Typed in again

Layout

Your logo, colour and signature on a set layout

Anything you can draw

What it costs

Part of Pro 365, S$365 a year for every module

Nothing, if you already own it

Price

Part of Pro 365.
S$365 a year, everything.

Invoicing is part of Pro 365, with the P&L and every other app.kevinchia.sg module. Every feature on this page is included, with no cap on invoices. We set every business up ourselves.

Pro 365, monthly

S$49 / month

cancel any time

Unlimited invoices1
Your branding, the PayNow QR, sending and reminders
Quotes, credit notes and statements

Pro 365, yearly

S$365 / year

about S$30 a month, billed yearly

Everything in monthly, paid once a year
The full P&L and every other module
Every module we build later

Who owes you11 Sep 2026

Not yet dueS$4,820.00

1 to 30 days lateS$2,180.00

31 to 60 days lateS$960.00

61 to 90 days lateS$0.00

Over 90 days lateS$450.00

Owed to youS$8,410.00

Every open invoice by how late it is, with a statement one tap away for any customer.

RemindersOn

Before it is due

1 day before3 days before7 days before14 days before

On the day it is dueOff

Once it is late

1 day late3 days late7 days late14 days late30 days late60 days late

For an invoice due on 10 Sep, reminders go on 9 Sep, 11 Sep, 17 Sep and 24 Sep, and stop the moment it is paid.

Off until you switch it on. Only the days you tick, and only invoices you write.3

Features

Everything in it.

Your invoice

Your logo, colour and signature on every invoice, quote and email
Your own numbering, given out in order with no gaps
A service menu: your usual services at their usual price, picked as you type, price still changeable, and imported from your bookings services and shop products in one go
A discount on any line, and your own payment terms and notes
Duplicate last month’s invoice instead of starting again

Sending it

By email, from your business name, with replies coming to you
By WhatsApp or as a link, when that is how they talk to you
See when it is opened, on the invoice and in your list
Your own wording for every email and WhatsApp message
Approval first, if a team member’s invoice should wait for you

Getting paid

A PayNow QR for exactly what is due, from your UEN, mobile or VPA2
Paid in parts, a deposit and the rest, each with its own date
“I have paid” sends you a Telegram with a button to record it
A receipt emailed when you record a payment, if you want one
A late fee suggested on an overdue invoice, added only if you press it

Chasing

Reminders before and after the due date, on the days you pick3
They stop the moment it is paid, and never go out at night
Switch them off for one customer or one invoice
A Telegram to you when an invoice goes overdue
Send a reminder yourself from any invoice, in one tap

Quotes and other documents

Quotations and pro-forma invoices your customer accepts on their phone
One click turns an accepted quote into the invoice
Repeat invoices for rent, retainers and monthly fees, made on their date
Credit notes with their own numbers, for changing an invoice properly
Cancel with a reason, and the number and the record stay

GST and currency

GST at 9% on top of your prices or included in them4
Zero-rated and exempt lines on the same invoice
Titled Tax Invoice with your GST registration number when it should be
Invoices in other currencies, with the GST shown in SGD

Your P&L

Revenue posts itself when an invoice is issued, in the month it is dated6
Split by GST treatment, so your F5 boxes add up
Undo a payment and the revenue comes back out
A credit note after payment is recorded as a refund, not an edit to a filed month

Your customers

Their own page for every invoice, to view it, pay it and download the PDF
One sign-in with a code shows them every invoice from you
Filed in Contacts on its own, with their invoices on their record
A statement of account for any customer, sent in one tap

Reports

Who owes you, split into not yet due, 30, 60, 90 and over
Who owes the most, at a glance
How long each customer takes to pay, on average
Export the invoice list to CSV, the rows you have filtered to, in order
Unlimited invoices, with no monthly cap1

This is not the end
of this module.

Ask for something and it gets built. Every account has a Feedback button that raises a real ticket, read by the person who writes the code. If it would help more than one Singapore business it goes into the module and lands in every account, usually by the next working day.

Need it to work with a tool you already use? Ask the same way. We check that it can be done and tell you straight. You subscribe, by card or PayNow, we build the connection, and you try it on your own account. If we cannot make it work, you get your money back.

Before you sign up, hello@kevinchiahd.com reaches the same place.

From a customer

“An entry point for a small start-up, without being overwhelming.”

“Looking for an easy way to manage my small business, I came across app.kevinchia.sg. This solution has an entry point for a small start-up, not overwhelming, while having more sophisticated features for future scaled-up operations. Had a chance to speak to the founder Kevin and was greatly encouraged that he listens to his clients, big or small, and is always open to see how he can improve the client experience. app.kevinchia.sg not only provides a solution, but provides the relationship management as if you are a big corporate. Very glad to chance upon this software.”

Shirley Ong · Pangolin Creatives Pte Ltd

Read every review

It does not stop at the invoice

The rest of your back office is on the same system.

A paid invoice lands in the same P&L as your receipts, your payroll and your shop orders, and the customer it was for is the same customer in your contacts. Nothing has to be joined up by hand.

Invoice sent→ Paid by PayNow→ In the P&L→ GST worked out→ On the customer’s record

Invoicing is part of Pro 365: every module for S$365 a year, or S$49 a month, plus every module we build after you subscribe.

See the P&L See Pro 365

Questions

Frequently asked.

How much does app.kevinchia.sg invoicing cost?

It is part of Pro 365: S$49 a month, or S$365 a year paid yearly, which works out about S$30 a month. That covers unlimited invoices with every feature on this page, the full P&L, and every other app.kevinchia.sg module. Email us and we set your business up ourselves. If you already pay for a single module, you keep your plan and your price.

Does the invoice have a PayNow QR?

Yes. Every invoice carries a PayNow QR for exactly the amount due now, with the invoice’s own reference in it, and your customer cannot change the amount. It works with a UEN, a mobile number or a PayNow VPA, and the money goes straight into your own account.

How do I know they have paid?

Your customer taps “I have paid” on their invoice and you get a Telegram with a button to record the payment. You can also record it yourself from the invoice, in full or in part. Either way the balance updates. The sale was already in your P&L from the day you issued the invoice.

Can app.kevinchia.sg chase late payments for me?

Yes. Switch reminders on and pick the days, before and after the due date. app.kevinchia.sg emails your customer until the invoice is paid and stops the moment it is. Reminders are off until you switch them on, and you can turn them off for any one customer or invoice.

Can customers accept a quotation online?

Yes. Send a quotation or a pro-forma invoice by email, WhatsApp or link. Your customer reads it and accepts it on their phone, and one click turns it into the invoice.

Does it do GST invoices?

Yes. If you are GST-registered, GST is worked out at 9% on top of your prices or included in them, and you can mark individual lines as zero-rated or exempt. The invoice is titled Tax Invoice and carries your GST registration number.

Can I split an invoice into a deposit and the rest?

Yes. Choose to be paid in parts and set each part as a percentage or an amount, with its own date. The last part is always what is left, so the parts always add up to the total, and the QR asks for the part that is due now.

What about invoices I already sent from somewhere else?

Leave them where they are. Start with the next invoice you send. There is nothing to import, and you can set your numbering to carry on from where you are.

Stop chasing it yourself.

Send your next invoice with a PayNow QR on it, and let the reminders do the asking. Email us and we set your business up ourselves.

Already have an account? Go to your invoices

Invoicing is part of Pro 365, which is S$49 a month, or S$365 a year paid yearly (about S$30 a month). Pro 365 has no limit on the number of invoices, includes every invoicing feature on this page and every other app.kevinchia.sg module, and includes every module built after you subscribe.
The PayNow QR follows the EMVCo standard, and the amount in it cannot be changed by the person paying. It is drawn for invoices in Singapore dollars. The money goes directly from your customer to your own account; app.kevinchia.sg does not hold or move it. Some banking apps let the payer edit the reference, so “I have paid” and your own bank statement remain how a payment is confirmed.
Reminders are sent by email, only once you switch them on, and only for invoices you write yourself. At most one reminder goes out for an invoice in a day, only between 9am and 7pm Singapore time, and none goes once the invoice is paid, cancelled or switched off.
GST is 9% and applies only from the registration date you record on your own account. Figures are worked out from the invoices you enter; app.kevinchia.sg does not file anything with IRAS on your behalf. This is not tax or accounting advice. Figures shown in the screens on this page are illustrative.
The comparison is with an invoice written in a word processor or spreadsheet and sent as a file, which is how most small businesses in Singapore begin. If a row here is wrong, tell us at hello@kevinchiahd.com and it will be corrected.
Revenue is recorded in your P&L on the invoice date, split by GST treatment, and GST is owed for that quarter. A payment only moves the money. Cancelling or deleting an unpaid invoice takes the sale back out. A credit note is recorded on its own date, so a month you may already have reported is never rewritten.

Send the invoice.Get paid on it.

Write it once.The rest follows it.