How to Use
BillZap: complete guide.

First-time setup (3 minutes)

When you open BillZap for the first time, you'll see a 4-step onboarding flow. Don't skip these steps — they take 3 minutes and they save you hours later.

Step 1: Choose your language

The very first screen asks which language you want to use. This is the app interface language, not the voice billing language (which can be different).

Pick whichever language you read and write most comfortably. You can change this later from Settings → Language.

Step 2: Add your business details

This is the screen where you enter:

• Business name — e.g., "Tamil Wholesale Co." or "Sharma Kirana Store"
• Owner name — your name as it appears on documents
• Phone number — your WhatsApp Business number
• GSTIN (optional) — your 15-digit GST number, if registered
• State — used for GST place-of-supply calculation

Tip: Don't have a GSTIN? Leave it blank. BillZap works fine without one — your invoices will say "Bill of Supply" instead of "Tax Invoice."

Step 3: Add your UPI ID

This is the single most important field. Your UPI ID is what generates QR codes on every invoice. Customers scan, money lands in your bank account. Done.

Format examples:

9876543210@paytm
yourname@okicici
business@ybl
9876543210@upi

If you don't know your UPI ID, open your UPI app (PhonePe, GPay, Paytm), tap "My QR" or "Receive Money" — the UPI ID will be shown on screen. Copy it exactly and paste into BillZap.

Critical: Test it once. Send ₹1 to the UPI ID using any UPI app. If it works, you're set.

Step 4: Set your PIN

Choose a 4-digit PIN. This unlocks the app every time you open it (or after 60 seconds of being in the background).

Important: Write this PIN down somewhere safe. There's no "Forgot PIN" via email.

How to create your first invoice

Before voice billing, let's create one invoice the normal way so you understand the flow.

Step 1: Tap the big "+" button

On the home screen, the large neon green "+" button creates a new invoice.

Step 2: Add the customer

You'll see a customer selector. You have three options:

1. Pick from existing customers — once you've billed someone before, they're saved
2. Walk-in customer — for one-time customers (no name needed)
3. Add new customer — opens a quick form

Step 3: Add items

Tap "Add item." You can type the item name, search existing products, or use voice. Enter price and quantity.

Smart amount tip: Type 2k instead of 2000. Type 1.5L instead of 150000. BillZap understands Indian shortcuts.

Step 4: Choose tax type

By default, BillZap applies GST based on your registered state and the customer's state. For same-state sales: CGST + SGST. For different-state: IGST. For non-GST-registered: No tax (Bill of Supply).

Step 5: Review and save

Tap "Save & Generate". Your invoice is created. PDF is auto-generated. UPI QR is embedded.

How to create an invoice with your voice

This is the feature that changes your life. Once you learn it, you'll never go back to typing.

Step 1: Tap the microphone icon

On the home screen, next to the "+" button, you'll see a microphone icon with a small neon dot. Tap it.

Step 2: Choose your voice language

A bottom sheet asks which language you'll speak. Pick the one you'll naturally use behind the counter. This can be different from your app interface language.

Step 3: Speak the invoice

Press and hold the big microphone button. Speak naturally. Examples that work:

Tamil:

"Rameshku 2 kilo sugar 50 rupees, 1 kilo salt 20 rupees"

Hindi:

"Sharma ji ke liye do kilo chini paachas rupaye, ek kilo namak bees rupaye"

Mixed (very common in India):

"Rameshku 2 kilo sugar 50 rupees, 1 packet biscuits 25 rupees"

Release the button when you're done. BillZap shows a "Listening… processing…" indicator for about 1-2 seconds.

Step 4: Review and confirm

BillZap extracts the customer name, items, rates and quantities, and total. You can edit any field manually, then tap "Looks good" — your invoice is created.

Voice billing tips

1. Speak naturally. Don't try to "talk like a robot."
2. Use number words. "Two kilo" or "do kilo" works better than "2 kilo" sometimes.
3. Include the customer name first. "Rameshku 2 kilo sugar" parses better than "2 kilo sugar Rameshku."
4. Speak each item separately. Pause briefly between items.
5. Use Indian unit words. "kilo," "gram," "packet," "dabba," "peti," "dozen" — all recognized.

How to add UPI QR to your invoices

This is automatic if you set up your UPI ID during onboarding. Every invoice you generate will have a scannable UPI QR code in the bottom-right of the PDF, a tappable UPI link in the WhatsApp message body, and an amount pre-filled to the invoice total.

To change your UPI ID later

1. Settings → Business Profile → UPI ID
2. Edit and save

All future invoices use the new ID. Past invoices keep the old QR (so customers paying late still pay correctly).

How to send an invoice via WhatsApp

The most-used feature in BillZap. Used in 78% of beta-tester invoices.

1. Open the invoice from the home screen or Invoices tab
2. Tap the green "Share via WhatsApp" button
3. Pick the contact
4. Tap Send

The message is pre-filled with a greeting in your customer's language, the invoice number, the total amount, the UPI link, and the PDF attachment.

Example for a Tamil customer:

"Vanakkam Ramesh!

Invoice #INV-2026-0142 — ₹460/-

UPI link: upi://pay?pa=9876543210@paytm&am=460

[Invoice.pdf attached]

— Tamil Wholesale Co."

How to use Day Close (replace your paper notebook)

The Day Close feature is BillZap's answer to the paper notebook every Indian shopkeeper keeps.

When you mark an invoice paid

Every time you tap "Mark Paid" on an invoice, BillZap asks how: Cash, UPI, Bank Transfer, Cheque, or Other.

How to view today's Day Close

1. From the home screen, tap the "Day Close" tab (third icon at bottom)
2. You'll see today's total, split by payment method

TOTAL COLLECTIONS: ₹14,470
─────────────────────────
CASH:    ₹3,450 (3 txn)
UPI:     ₹8,920 (2 txn) ← biggest
BANK:    ₹2,100 (1 txn)
─────────────────────────
6 invoices · 0 expenses

Business day timing

BillZap's business day starts at 4:00 AM (not midnight). This matches how Indian shopkeepers actually think about their day — your night shift sales are part of today, not tomorrow.

How to send festival greetings to customers

This feature drives massive customer loyalty for almost zero effort.

How festival reminders work

BillZap has 17+ Indian festivals pre-loaded:

• Pan-India: Diwali, Holi, Eid, Christmas, New Year, Raksha Bandhan
• Regional: Pongal (TN), Onam (KL), Baisakhi (PB), Ganesh Chaturthi (MH), Durga Puja (WB)
• Cultural: Makar Sankranti, Krishna Janmashtami, Navratri, Karwa Chauth

The day before each festival, BillZap sends you a notification:

"🪔 Diwali is tomorrow. Send greetings to 47 customers?"

Tips for festival greetings

1. Send the day before, not the day of. Festival day is the busiest day — your message gets lost.
2. Don't add a sales pitch. "Wishing you happy Diwali. P.S. 20% off everything!" feels desperate.
3. Personalize the signature. Use your business name + owner name.

How to change the app language

You can change the BillZap interface language anytime — independent of your voice billing language.

1. Tap the Settings icon (gear, top right)
2. Tap "Language"
3. Pick from 12 languages

How to back up your data (and why you must)

This is the most important section of this entire guide. Please read it.

Why backups matter

BillZap is offline. Your data lives on your phone. If your phone is lost, stolen, dropped in water, or factory-reset — your data is gone forever unless you've backed up.

How to create a backup

1. Settings → Backup & Restore
2. Tap "Create Backup Now"
3. Enter your PIN (this encrypts the file)
4. Choose where to save: Google Drive (recommended), Email, WhatsApp, or phone storage

The .billzap file is encrypted. Only your PIN can unlock it.

How often to back up

Daily is best. Weekly is acceptable. Monthly is risky.

How to set up PIN + Fingerprint lock

Change your PIN

1. Settings → Security → Change PIN
2. Enter current PIN
3. Enter new PIN twice

Enable/disable fingerprint

Settings → Security → Biometric Lock — toggle on/off.

What if I forget my PIN?

There's no "Forgot PIN" option. If you forget it, you have two options:

1. Restore from a backup — install fresh, restore, set new PIN
2. Reset the app — lose all data, start over

This is by design. PIN-less recovery would mean BillZap could read your data — defeating the entire encryption purpose.

Troubleshooting common issues

Voice billing isn't understanding me

Fix: Move to a quieter spot, slow down slightly, check microphone permission in Settings → Apps → BillZap → Permissions.

UPI QR isn't scanning

Fix: Settings → Business Profile → check UPI ID is correct. Test with another UPI app.

App is slow on my phone

Fix: Free up 500MB+ phone storage, close other apps, restart phone.

Can't restore from backup

Fix: Make sure you're using the correct PIN (the one active when the backup was created).

You're now a BillZap power user

You've covered every major workflow. The shopkeepers who get the most out of BillZap follow this pattern:

1. Week 1: Use it for every invoice. Don't skip back to paper.
2. Week 2: Start using voice billing for at least 50% of invoices.
3. Week 3: Set up automatic festival greetings. Send Day Close to your spouse/accountant daily.
4. Week 4: Back up to Google Drive. Test the restore on a friend's phone.

By Week 4, BillZap has paid for itself ten times over — in time saved, in late nights you didn't have to spend on your notebook, and in customer payments that landed in your account the moment the customer scanned a QR.