Customer bill portal — find old bills with phone OTP

Why customers need access to old bills

The most common reasons a customer asks for a past invoice:

• Warranty claims — the manufacturer or service centre needs proof of purchase with the date and item details.
• Product returns — your own shop's return policy requires the original bill.
• GST input tax credit — business buyers need a valid GST invoice to claim ITC. A duplicate copy with your GSTIN and their GSTIN is essential.
• Expense reimbursement — employees who made a purchase on behalf of their company need an invoice to submit to accounts.
• Personal record-keeping — high-value purchases like electronics, furniture or jewellery are often re-insured; the invoice is required.

Without a portal, every one of these requests comes to your staff — pulling their attention away from serving current customers.

What the BillRaja customer bill portal is

The customer bill portal is a web page at billraja.in/customer that any customer can open in a phone browser. It is not a separate app — no download, no account creation. The customer simply:

1. Enters the mobile number they gave at the time of purchase
2. Taps "Send OTP"
3. Enters the one-time password received by SMS
4. Views and downloads all past invoices from your shop

The entire process takes under a minute. The customer gets their invoice as a PDF they can save, print, or share.

How a shop enables it — what you need to do

There is only one action on the shop's side: always enter the customer's mobile number when creating an invoice. BillRaja links the invoice to that number. When the customer later visits the portal and enters the same number, all their invoices from your shop appear.

Best practices when billing customers:

• Ask for the mobile number at checkout — frame it as "for your digital invoice"
• Double-check the number before saving to avoid wrong links
• If a customer has multiple numbers, use the one they are most likely to remember or have access to
• For B2B customers, enter the GST contact number or the buyer's billing mobile to allow the accounts team to retrieve invoices

You can also share a specific invoice directly from BillRaja over WhatsApp or email at any time — the portal is a self-serve option, not the only method.

The OTP security model

The portal uses Firebase OTP authentication — the same technology behind major Indian banking and e-commerce apps. Here is what makes it secure:

• Phone-number ownership proof — only someone who has access to the registered SIM receives the OTP via SMS. No password to guess or phish.
• Short-lived OTPs — OTPs expire in under 5 minutes. An intercepted OTP quickly becomes worthless.
• Session expiry — after a period of inactivity the portal session ends. A new OTP is required to view bills again. This prevents access by someone who picks up an unlocked phone.
• Read-only access — the portal never exposes other customers' data and cannot modify any invoice. It is strictly a view-and-download interface.
• No stored password — there is no password to leak in a data breach. Each session is authenticated fresh.

Practical scenarios where the portal saves time

Retail shop — warranty claim 6 months later

A customer bought a mixer from your electronics shop in December. It breaks in June. The service centre asks for the purchase bill. Without a portal, the customer calls your shop, your staff searches through records, finds the bill (hopefully), and sends a WhatsApp. With BillRaja's portal, the customer opens billraja.in/customer on their phone, enters their number, and downloads the December invoice themselves — no call needed.

Medical / pharmacy — GST receipt for insurance reimbursement

A patient bought medicines on three separate visits and now needs the invoices to submit a reimbursement claim. The portal lists all three bills. The customer downloads PDFs and attaches them to the insurance form — done in two minutes with zero intervention from your billing counter.

Gym / coaching centre — fee receipt for employer reimbursement

A gym member's employer pays for fitness memberships as part of employee benefits. The HR department needs a monthly GST invoice. Instead of the member visiting the counter every month, they log in to the portal and download the receipt themselves. Combined with BillRaja's membership workspace, the invoice is already generated the moment you collect the fee.

Telling customers about the portal

The portal only saves you time if customers know it exists. A few ways to spread the word:

• Add a footer line to every invoice — "View & download your bills anytime at billraja.in/customer"
• A small sticker at the billing counter — "Lost your bill? Find it on your phone at billraja.in/customer"
• Mention it verbally when handing over a receipt — "Your bill is also available on your phone — just scan your number at billraja.in/customer"

Once a customer has used the portal once, they tend to remember it — and it significantly reduces repeat requests to your staff.