Invoice software for Singapore that turns every job into a receipt or invoice

If you make invoices in a Word template, you know the routine: copy last month's, change the number, retype the items, work out the GST, export a PDF, then try to remember who has paid. AQUORIA O.N.E skips the template. Every order or job you record can be printed as a receipt or opened as an A4 invoice, with its own number, the tax worked out, a pay-by date and how to pay.

On Essential or Business · no card needed

Because the invoice comes from the order, the amounts always match what the customer bought, payments come off the balance as they arrive, and your invoices list, statements and reminders agree with each other.

Receipts and A4 invoices from the same order

Print receipt gives a narrow receipt for the counter. A4 invoice gives the same order on a full page, for professional services, contracts and business customers: your logo and details, the client's details and registration number, each line with quantity, unit price and amount, the total, what's been paid and the balance due. Both come in the customer's own language.

The document names itself correctly. When a GST-registered shop has charged tax, it's a Tax invoice. While money is still owed, it's an Invoice. Once everything is paid, the receipt says Paid in full. Thank you!

In Singapore, entering your UEN when you sign up fills in your registered address and PayNow for you, so your first invoice already carries the right business details.

Invoice numbers, drafts and payment terms

Choose how your invoice numbers start, such as INV- or your initials, and Settings shows what the next one will be. Opening an A4 invoice doesn't issue it: until you press Issue invoice it's a draft with no number and no pay-by date, so you can finish the work and settle the amount first. Once issued, its number never changes.

Set the days clients have to pay, and the invoice prints Payment due within 30 days along with the pay-by date. A business customer can have their own terms, which then apply on their invoices, statements and reminders. Add how clients can pay: your bank name, account name and number, and for overseas clients the SWIFT code, bank address and branch code for a telegraphic transfer.

GST on invoices, and the GST F5 figures

In Settings, enter your tax rate, your GST registration number and whether your prices include tax. Every order then shows the GST inside the price or on top of it, and receipts and invoices print it. Finance › Tax & accounting sets your figures out in the GST F5 boxes for each quarter, from standard-rated supplies to net tax to pay, worked out from your orders and expenses. Check them with your accountant before you file.

If your shop isn't GST-registered, leave the rate empty: your invoices carry no GST and are titled Invoice rather than Tax invoice.

Invoices that fit the job

The invoice carries what the job needs. A car workshop's invoice shows the car and its mileage; a rental or a car sale shows the car the job is about. An express surcharge prints as its own line, so the lines always add up to the total. If an invoiced order is cancelled, the invoice keeps its number and shows as Cancelled, with a credit note for what was left on it.

Moving over from spreadsheets or another app? Import the invoices your customers haven't paid yet. Each one is added on its own invoice date, so it isn't counted in this month's sales, and shows in Money owed with reminders if you have them on. The same invoice imported twice is skipped.

A PayNow QR on every invoice

In Singapore, an A4 invoice prints a PayNow QR for exactly what's owed, quoting the invoice number, paid straight to your own PayNow: your UEN, or your mobile number for many home businesses. A client who'd rather pay by card can open the order link and pay through your own payment account. Each payment comes off the balance, and a part payment leaves the rest showing as owed.

The invoices list, credit notes and CSV

Invoices lists every invoice you've issued, with tabs for All, Unpaid, Overdue and Paid, a search by invoice number or client, a month filter and the total still to collect. Open any one as a PDF, or press Download list (CSV) for your accountant. Finance can also download your sales in the import format of Xero or QuickBooks Online: a file you import yourself, not a live sync.

Spotted a mistake after issuing? Issue a credit note. It takes part or all of an invoice back with a numbered credit note of its own, works out the tax in it in proportion, and either gives the money back the way it was paid or takes it off what's owed. A credit note counts in the period it's issued, so a GST quarter you've already filed stays as filed.

Statements for business accounts

Customers on a business account get a monthly statement: owed at the start of the month, charged this month, paid this month and owed at the end, with the month's orders listed. Print it or email it. Record a payment against the statement and it's applied to the oldest unpaid orders first, the way most accounts teams pay.

Chasing what's owed, politely

Finance › Money owed shows who owes you what, split into up to 30 days, 31–60 days and over 60 days, with a Send reminder button on each customer. Turn on automatic payment reminders and the same polite message, with the amount and a link to pay, goes after the number of days you choose, then every few days, up to a limit you set, between 10 am and 7 pm. For business accounts, the days count from the invoice's pay-by date.

Send reminder goes through whichever channel you've connected in Settings: your own SMS account, email mailbox or Telegram bot. Automatic reminders need your own SMS account connected. You can also press Send to customer on any order to open WhatsApp or email on your own device with the invoice number, the amount, the pay-by date and the link.

How it works

  1. 1Set your invoice prefix, payment terms, GST details and how clients can pay in Settings.
  2. 2Record the job or order, open A4 invoice, and press Issue invoice when the work and the amount are final.
  3. 3Send it, take payments as they arrive, and follow up from Money owed, statements and reminders.

What you'll use

Plan: Essential or Business

Questions

Invoice vs receipt: what's the difference?

An invoice asks to be paid: it has a number, a pay-by date and how to pay. A receipt shows a payment was made. In AQUORIA O.N.E both come from the same order. A4 invoice issues a numbered invoice for a client; Print receipt gives the counter receipt, which says Paid in full once nothing is owed.

What do Singapore invoices need for GST?

A tax invoice from a GST-registered business generally shows its name, address and GST registration number, an invoice number and date, the customer's details, what was supplied, the amount before tax, the GST and the total. AQUORIA O.N.E prints these on a Tax invoice once your rate and registration number are set. Check IRAS's current rules for your case.

Can I make an invoice without GST?

Yes. If your shop isn't GST-registered, leave the tax rate empty and your invoices carry no GST; they're titled Invoice, not Tax invoice. You still get running invoice numbers, pay-by dates, your payment details and a PayNow QR for the amount owed, and your sales figures are shown for reference.

Can I send my invoices to my accountant?

Yes. Invoices › Download list (CSV) gives every invoice with its number, date, amount and status. Finance can also download your sales in the import format of Xero or QuickBooks Online, ready to import. These are files you download; AQUORIA O.N.E doesn't sync live with accounting software.

Are invoices included in Essential?

Yes. Receipts, A4 invoices, invoice numbers, GST, credit notes, the invoices list, statements and payment reminders are on Essential at S$29 a month, after a 14-day free trial with no card needed. Business, at S$149 a month, adds bills to pay, bank matching and delivery orders.

Try it free for 14 days, then S$29 a month (Essential) or S$149 a month (Business). No card needed.