Creating and sending professional invoices is the core of getting paid. This tutorial covers the entire invoicing process in Nastrum Books: creating an invoice, adding a customer, entering line items with quantities and discounts, applying tax automatically, previewing the PDF, and saving it ready to send.
The whole process takes about 2 minutes once you have your company set up.
New to Nastrum Books? Set up your company first - it takes 3 minutes.
Every step from the video is written out below with additional detail.
Step 1: Go to the invoices page
Click Invoices in the left sidebar under the SALES section. You will see the invoices list page with:
- KPI cards at the top - total invoices, total revenue, pending amount, and overdue amount at a glance
- Search bar - find any invoice by number or customer name
- Filters - filter by status (all, draft, sent, paid, overdue), customer, time period, and sort order
- Status tabs - click All, Draft, Sent, Paid, or Overdue to quickly filter
Click the blue + New Invoice button in the top right corner.
Step 2: Understand the invoice form
The new invoice form opens with several fields pre-filled:
Invoice header
- Invoice # - auto-generated sequentially (INV-0001, INV-0002, etc.). You can customise the prefix and numbering in Settings.
- Status - starts as “draft”. Changes to “sent” when emailed, “paid” when payment is recorded.
- Issue date - defaults to today. Change it if you are backdating or scheduling.
- Due date - defaults to 30 days from the issue date. This is configurable in Settings under invoice defaults.
Invoice type
At the top of the form, you can toggle between:
- Cash Sale - for immediate payment (over-the-counter sales)
- Credit Sale - for invoices with payment terms (most common)
Step 3: Select or add a customer
Click the Customer dropdown and start typing a name. If the customer already exists in your system, select them from the list.
Adding a new customer inline
If this is a new customer, click + Add new customer at the bottom of the dropdown. A quick-add modal appears with three fields:
- Name (required) - the customer’s name or business name
- Email (required) - for sending invoices by email
- Phone (optional) - for your reference
Click Save customer. The customer is added to your customer list and automatically selected on this invoice. You do not need to leave the invoice form.
After selecting a customer, the form also shows:
- Currency - auto-set based on the customer’s default currency (you can change it per invoice)
- GST/IRD Number - the customer’s tax identification number, if saved on their profile
- Payment terms - shows the terms (e.g., “Terms: 30d”)
Step 4: Add line items
The LINE ITEMS section is where you describe what you are billing for.
Adding your first item
Each line item has the following fields:
- Item / Description - select from your saved items catalogue or choose “Manual” to enter freely
- Description - a text description of the item or service
- Qty - quantity (defaults to 1)
- Rate - unit price
- Disc % - discount percentage per line item (e.g., 5 for 5% off)
- Tax - select the applicable tax rate (e.g., GST 15%, VAT 5%, or No Tax)
- HSN/SAC - tax classification code (required for GST invoices in India)
- Amount - auto-calculated: (Qty x Rate) minus discount, before tax
Example: adding a single item
In the video, we add a Wooden Chair:
- Quantity: 1
- Rate: $135.00
- Discount: 5%
- Tax: GST 15%
- Amount after discount: $128.25
The tax is calculated on the discounted amount, not the original rate. This is the correct treatment in most tax jurisdictions.
Adding multiple line items
Click + Add line item to add more rows. In the video, we add a second item:
- Plastic Chair, quantity 2, rate $90.00 each, 5% discount, GST 15%
- Line amount: $171.00
You can add as many line items as needed. There is no limit.
Step 5: Review the totals
The right side of the invoice form shows a running calculation:
- Subtotal - sum of all line amounts after discounts
- Tax (e.g., GST 15%) - total tax calculated across all line items
- Discount - you can also apply an overall invoice-level discount (fixed amount or percentage)
- Total - final amount including tax
- Balance due - total minus any payments already recorded
In the video, the invoice totals:
- Subtotal: $299.25
- GST 15%: $44.89
- Total: NZ$344.14
All calculations happen in real time as you type.
Step 6: Add notes, terms, and footer
Below the line items, three optional text fields let you add information that appears on the invoice PDF:
- Notes - a message to your customer (e.g., “Thank you for your business!”)
- Terms & Conditions - payment terms (e.g., “Payment is due within 30 days.”)
- Footer - footer text that appears at the bottom of the PDF
You can set defaults for all three in Settings > Invoice Defaults so you do not have to type them on every invoice.
Additional fields
- Reference / Memo - internal reference (e.g., project name, PO number). This is for your records and does not appear on the PDF.
- Tags - add tags to categorise invoices for filtering and reporting.
Step 7: Preview your invoice
Click Preview to see exactly what your customer will receive. The preview shows:
- Your company name and address in the header
- Invoice number, issue date, and due date
- Customer billing details
- Line item table with descriptions, quantities, rates, discounts, and amounts
- Tax breakdown
- Gross amount, discounts, subtotal, tax, and total
- Terms and conditions
- Notes
If everything looks correct, click Save Invoice. If you need to make changes, close the preview and edit the form.
Step 8: Invoice saved - what you can do next
After saving, you land on the invoice detail page. This is the command centre for this invoice. The action buttons across the top give you everything you need:
- Record Payment - log a full or partial payment when your customer pays
- Edit - make changes to the invoice
- Send Email - email the invoice as a PDF attachment directly to your customer
- Duplicate - create a copy of this invoice (useful for recurring billing)
- Preview PDF - view the full PDF document
- Download PDF - save the PDF to your computer
- Print - print directly from your browser
- Submit for Approval - if your team uses an approval workflow before sending
Below the action buttons, you can navigate between tabs:
- Overview - the invoice content
- Payments - payment history for this invoice
- Attachments - upload supporting documents
- Email history - log of every email sent for this invoice
- Approval - approval status and comments
Step 9: Preview and download the PDF
Click Preview PDF to see the final professional PDF document. This is exactly what your customer receives.
The PDF includes:
- Header - your company name (linked in blue), full address, email, and phone number
- Invoice details - invoice number, issue date, due date
- Bill to - customer name and email
- Line item table - description, quantity, rate, discount percentage, and amount for each item
- Calculation breakdown - gross amount, discounts (shown in green), subtotal, tax, and total
- Amount in words - the total written out (e.g., “New Zealand Dollars Three Hundred Forty-Four and 14/100 Cents Only”)
- Notes and terms - your custom messages
From the PDF preview, you can:
- Download PDF - save to your computer
- Print - send to printer
- Send Email - email it directly to the customer
Understanding invoice statuses
Every invoice in Nastrum Books has a status that updates automatically:
| Status | Meaning |
|---|---|
| Draft | Created but not yet sent to the customer |
| Sent | Emailed to the customer |
| Viewed | Customer opened the email (if tracking is enabled) |
| Partially Paid | Customer made a partial payment |
| Paid | Full payment received |
| Overdue | Due date has passed with balance remaining |
You can filter your invoice list by any of these statuses to see exactly where your receivables stand.
Tips for creating invoices that get paid faster
Based on research into payment behaviour, here are practical tips:
- Send the invoice immediately - invoices sent on the same day as the work get paid 1.5x faster on average
- Set clear due dates - “Net 30” is standard, but “Net 14” or “Due on receipt” gets money faster
- Include your bank details - make it easy for the customer to pay by including your bank account details on the invoice
- Use line item descriptions - “Consulting services” is vague. “Website redesign - phase 1 (40 hours)” is clear.
- Apply discounts visibly - showing a discount (even 5%) makes customers feel they are getting a deal and motivates faster payment
- Send payment reminders - a gentle reminder 3 days before the due date significantly reduces late payments
How invoicing in Nastrum Books compares
Most accounting software treats invoicing as a basic feature. Nastrum Books includes advanced invoicing capabilities on every plan, including the free one:
- Automatic tax calculation - GST, VAT, and custom tax rates calculated per line item
- Per-item discounts - percentage or fixed amount discounts on individual line items
- Invoice-level discounts - an additional overall discount
- Multi-currency invoicing - send invoices in any of 45+ currencies with automatic exchange rates
- Professional PDF generation - client-side PDF rendering with your logo, branding, and amount in words
- Inline customer creation - add new customers without leaving the invoice form
- Email delivery - send invoices directly from the app via Brevo, EmailJS, or custom SMTP
- Approval workflows - require approval before invoices can be sent (useful for teams)
- Email tracking - see when invoices were sent and view the email history
- Duplicate invoices - one-click copy for recurring billing
- Tags and filtering - organise invoices by project, department, or any custom category
All of these features are available on every plan, including the free Solo plan.
Frequently asked questions
Can I customise the invoice number format?
Yes. Go to Settings > Invoice Defaults. You can set a custom prefix (e.g., “INV-”, “NB-”, or your company initials), starting number, and numbering pattern.
Can I add my logo to invoices?
Yes. Upload your logo in Settings. It appears automatically on every invoice PDF, estimate, and statement.
Can I send invoices in a different currency?
Yes. When creating an invoice, select any of the 45+ supported currencies from the Currency dropdown. The exchange rate is applied automatically based on live rates. Your reports still show everything in your base currency.
Can I create recurring invoices?
Yes. Go to Recurring Invoices in the sidebar to set up automatic invoice generation on a schedule (weekly, monthly, quarterly, or custom). Each recurring invoice is created as a draft and can be set to auto-send.
What happens when a customer pays?
Click “Record Payment” on the invoice. Enter the amount, payment date, payment method (bank transfer, cash, card, etc.), and which bank account received the money. The invoice status updates automatically, and a transaction is created in your banking records.
Can I send the invoice by email from the app?
Yes, if you have configured email delivery in Settings. Nastrum Books supports Brevo (free tier: 300 emails/day), EmailJS, and custom SMTP. The customer receives a professional email with the invoice PDF attached.
Is there a limit on how many invoices I can create?
No. All plans, including the free Solo plan, allow unlimited invoices. There is no monthly or annual cap.
Can I add attachments to an invoice?
Yes. On the invoice detail page, go to the Attachments tab to upload supporting documents such as contracts, delivery notes, or photos.
Does Nastrum Books support partial payments?
Yes. When recording a payment, enter any amount up to the balance due. The invoice status changes to “Partially Paid” and shows the remaining balance. You can record multiple payments until the invoice is fully paid.
Can I duplicate an invoice?
Yes. Click “Duplicate” on any invoice to create an identical copy with a new invoice number and today’s date. This is useful for regular clients who receive the same invoice each month.
Ready to create your first invoice? Sign in to Nastrum Books or create your free account if you have not set up yet.