What you’ll be able to do after this guide
Log in to the cashier screen and choose the store warehouse → add products to the cart (scan / browse / search) → apply discounts and attach a customer if needed → collect cash or QR/MoMo → print the receipt and (optionally) let the customer pick up the VAT invoice themselves → hold the order / recall it when needed → and process returns and refunds correctly in the books. In the end: you’ll be able to run a full sales shift at the counter, and every order will sync inventory + customers with the online sales system.
Not familiar with the overview yet? Read the Point-of-Sale (POS) article first to understand what POS can do.
Preparation
1. A GTG CRM account with Create POS sale permission (Point-of-sale sales). — Without this permission, you won’t be able to complete an in-store order.
2. The store warehouse has already been set up in the system, and the products have prices, barcodes (if scanning), and stock in that warehouse. — POS deducts stock from the store warehouse; barcode scanning requires a barcode on the product.
3. (If collecting QR/wallet payments) MoMo/VNPay has been enabled and configured in the online store’s payment settings. — POS uses the same payment configuration; only ready methods are shown.
4. (If processing returns) The account has return permission (higher than a regular cashier). — Returns reverse cash flow, so they require separate permission; without it, the Returns section is hidden.
5. (Optional) A 58mm/80mm thermal printer connected to the counter computer. — For printing receipts and opening the cash drawer automatically.
Step 1 — Log in to POS and select the store warehouse
Open pos.gtgcrm.com in the browser on the counter computer, and sign in with your GTG CRM account.
If you have multiple workspaces/stores, choose the correct store to sell from.
On first use: go to Settings (Cài đặt) → select the store warehouse (store warehouse).
✅ Expected result: The POS screen appears (without the CRM interface), the top bar shows the store warehouse name and cashier name. The product grid is visible in the middle of the screen.
Step 2 — Add products to the cart (scan / browse / search)
Scan the barcode with a USB scanner (place the cursor in the scan field and scan), or type the code and press Enter.
Or browse the product grid: tap a product card to add it; tap a category tab to filter by group; scroll down to load more automatically.
Or search: type the product name/code into the search box, then tap a result to add it.
Adjust quantities in the cart: click + / −, or tap directly on the quantity number to type a value (for example 12); remove a line with the trash can icon 🗑.
✅ Expected result: The product appears in the cart with the correct price; Total updates instantly each time you add/edit/delete. Out-of-stock products are dimmed and cannot be added.
💡 Tip: You can still sell without a scanner — just tap products in the grid or search by name.
Step 3 — (Optional) Apply a discount
Line-item discount: tap the discount button on the product line, then choose either amount or percentage (%).
Order discount: open the order discount field, then enter an amount or percentage.
✅ Expected result: The cart clearly shows Subtotal / Discount / Total; the total is recalculated by the server. If you enter a discount larger than the subtotal, the system rejects it and the total will never go negative.
Step 4 — (Optional) Attach a customer by phone number
In the customer field, enter the customer’s phone number.
✅ Expected result: If the number already exists in the CRM, the contact name appears instead of “Walk-in (Khách vãng lai)” and the order will be linked to that customer. If no number is entered, the order is treated as a walk-in customer — sales still proceed normally.
Step 5 — Cash payment
Click Pay (Thanh toán) → select Cash (Tiền mặt).
Enter the amount the customer gives using the numeric keypad, or tap the quick denomination buttons (10K–500K), or Exact (Đúng số tiền).
Click Confirm (Xác nhận).
✅ Expected result: The screen shows Total / Tendered (Tiền khách đưa) / Change (Tiền thối); after confirmation, the order is created (source POS), inventory is deducted immediately, the cart is cleared, and the cursor returns to the scan field for the next customer.
ℹ️ If you sell more than the available stock, the system blocks the sale and shows which product is short — it does not deduct any inventory.
Step 6 — Pay with bank QR / MoMo wallet
Click Pay (Thanh toán) → choose MoMo or VNPay (only shown if you have enabled/configured it).
Click to display the payment QR — the QR code appears on the customer-facing secondary screen.
The customer scans to pay: MoMo is scanned in the MoMo app (not with the phone camera); VNPay opens the VNPay QR page.
✅ Expected result: When payment is received, the order is completed automatically, inventory is deducted, and the receipt prints; a “payment received” notification appears in the 🔔 bell on the POS bar. If payment initiation fails, the cart is kept intact so you can try again.
Step 7 — Print the receipt and (optionally) open the cash drawer
The first time at each register: go to Settings → Printer (Máy in), choose the appropriate Connection (Kết nối) (System printer / WebUSB / Web Serial), select the 58mm/80mm paper size, enable/disable open drawer on cash sale, then Print test receipt (In thử).
From then on, each completed order will print a receipt automatically (and open the drawer for cash orders if enabled).
Need to reprint? Click Print again (In lại) on the just-completed sale screen, or open Recent sales (Đơn gần đây) and reprint any order.
✅ Expected result: The receipt prints correctly in Vietnamese with accents, including store details, item list, total amount, and change; reprints are marked RE-PRINT. If the printer has a problem, the order still completes — only a small message with a retry button appears.
Step 8 — VAT invoice: view tax and let customers self-issue the e-invoice
See tax included in the price: the cart and receipt clearly separate the VAT amount included in the price, by each product tax rate (for example 8%, 10%) — the total does not change.
New product without VAT yet: for stores that declare VAT, a newly created product that the store owner has not assigned a VAT rate to cannot be sold. When collecting payment, the screen shows “Tax rate has not been set for …. Please ask a manager to set it in Products and try again, or remove this item to continue.” If you remove that item from the order, the remaining items can still be sold. Products that already existed before continue to sell as usual.
Enable/disable VAT declaration: if the store has not declared VAT / does not declare VAT, turn it off in Settings — POS will not display or record tax.
Customers can self-issue e-invoices: if a customer requests a VAT invoice, they enter their information on their own phone, and the cashier does not need to retype the name, tax ID, or address. The receipt includes a QR code: the customer scans it with their phone, opens the Issue VAT Invoice page, fills in the buyer’s information, then taps Issue Invoice. The e-invoice is issued through the invoice provider you have connected.
The page customers see on their phone after scanning the QR code on the receipt.
Companies, business households, and individuals with tax IDs can all use this page. Customers fill in:
- Company, business household, or full name (required): the small text below reminds companies, business households, and individual businesses to enter the name and address exactly as shown on the registration certificate.
- Tax ID (required): businesses enter a 10-digit tax ID, or 13 digits if it is a branch. Business households and individuals usually enter a 12-digit personal identification number. The page reminds customers to enter it according to the tax ID notice or registration certificate, and this number will be printed on the invoice, so it must be checked carefully.
- Address (required).
- Email to receive invoice and Phone number: optional.
A business household enters a 12-digit personal identification number in the Tax ID field (the number in the image is a sample). The page accepts this number.
Above the Issue Invoice button, the page clearly states what this information is used for and who it will be sent to.
The page only checks whether the Tax ID has 10, 12, or 13 digits; it does not check whether the number belongs to the customer. If the customer enters a number with a different length (for example, 11 digits), the page shows the red message Invalid: Tax ID above the Issue Invoice button, keeps everything the customer entered unchanged, and does not issue any invoice yet. If the customer enters the wrong number but it still has 10, 12, or 13 digits, the page will still accept it. A mistyped 12-digit personal identification number will not be blocked by the invoice provider and will be printed on the invoice, so ask the customer to read it back before submitting. If the name or address is missing, or if the name or address exceeds the invoice provider’s character limit, the page clearly indicates which field needs correction.
After submission, the customer sees Information received and the line The VAT invoice is being issued for you.
If the invoice cannot be issued. If the customer scans the QR code on the receipt again, they will see a page saying Invoice could not be issued. For some errors (invalid tax ID, missing buyer name or address), the page states the reason clearly, for example: The buyer’s tax ID is invalid. Please compare it with the tax ID notice or registration certificate. For other errors, and with some invoice providers, the page only says the provider has not received this information yet and advises the customer: if resubmitting still does not work, contact the store.
ℹ️ Note: currently, clicking Resend does not change the information on an invoice that has not yet been issued. The page still shows that it has been received, but if the error is in the customer-entered information, that invoice still will not be issued. Customers cannot edit it themselves from this page yet, so they may need to go back and ask the store.
If the store has not enabled automatic invoice issuance for this order. If the store has not connected or has not enabled the automatic e-invoice issuance feature, customers scanning the QR code will see a clear "Not available yet" message — "The store has not enabled automatic invoice issuance for this order. You can try again, or contact the store." — instead of a promise that an invoice is "being issued" that never arrives. Customers can come back and try again after the store enables the feature, or contact the store directly for support.
The screen the customer sees when the store has not enabled automatic invoice issuance for this order — the customer can tap "Resend" to try again once the store has enabled it, or contact the store.
✅ Expected result: The cart/receipt shows the correct VAT amount for each tier; the receipt has a QR code so the customer can enter invoice details themselves; when the customer fills in their name, tax ID, and address and submits, they see Information received and the line The VAT invoice is being issued for you. A household business entering a 12-digit personal ID number into the tax ID field will have that number accepted by the page.
ℹ️ Issuing an e-invoice requires that you have already connected an invoice provider for the store. If you have not connected one yet, the receipt will still clearly state that this is not yet a valid VAT invoice.
Step 9 — Park and Recall
Customer hesitating/forgot their wallet? Tap Park to save the current cart.
Serve the next customer as usual.
Open the list of parked orders, then tap Recall to restore the previous cart.
✅ Expected result: After parking, the cart is empty and a parked-order entry appears (item count + total + time). When you Recall, the cart is restored with exactly the same lines, quantities, discounts, and assigned customer; the parked order remains intact even after refreshing the page.
Step 10 — Returns and refunds
Open the ⋯ menu on the POS bar → Returns (only visible if you have return permissions).
Select the order to return from the recent list (or enter the order code) → Load.
Enter the return quantity on the line to be returned, note the reason, then tap Issue refund.
✅ Expected result: A "Refund issued: " notification appears; returned items are added back into inventory (available for reuse); the order changes status to partially_returned/returned; an offsetting entry is recorded to balance the books. If you return more than was sold, the system will reject it.
Step 11 — Check the POS order and 360° activity feed in CRM
Open CRM (app.gtgcrm.com) → Orders: find the sale you just made, source POS.
If a customer was assigned: open that contact → Activity tab.
Open Orders → Activities to view the full in-store order feed.
✅ Expected result: The order appears with source POS, the correct total amount, and no shipping address; if a customer is linked, an activity "POS sale" appears on the customer’s timeline; all counter sales appear in the Activities feed of the Orders menu (filterable by seller/date).
Quick reference table of expected results
Log in to POS + select warehouse — The POS screen shows the warehouse name + cashier name, and the product grid is preloaded
Scan code / tap product — The product is added to the cart at the correct price; the total updates instantly
Tap quantity — A numeric keypad appears to enter the quantity directly
Apply discount — Subtotal / Discount / Total are shown; the server recalculates; discounts cannot exceed the subtotal
Link customer by phone number — The contact name appears instead of "Walk-in"
Accept cash + Confirm — Change is shown; the order (POS source) is created, inventory is deducted, and the cart is cleared
Accept QR/MoMo — The customer scans to pay; the order is completed automatically; a bell notification says "payment received"
Sell beyond stock — Blocked, the missing product name is shown, and inventory is not deducted
Print receipt / Reprint — Receipt is clearly in Vietnamese; reprints are marked RE-PRINT
View VAT — The tax portion included at each rate is clearly separated
Park → Recall — The cart is saved and then restored correctly (even after reloading the page)
Issue refund — Refund + stock return + reversing journal entry; returns above sold quantity are blocked
Check in CRM — POS-source order + 360° activity on the customer and in the Orders feed
Notes
You need the Create POS sale permission to complete an order; you need a separate return merchandise permission to use the Returns section — if you don’t have it, contact your workspace admin and log in again to receive the new permission.
POS deducts inventory from the selected store warehouse in Settings; each counter should save its own printer / paper size / cash drawer configuration.
QR MoMo must be scanned using the MoMo app, not the phone camera; only payment gateways that you have enabled and configured will appear at the counter.
Issuing e-invoices for customers requires that you have connected an invoice provider; if not connected yet, the receipt clearly states that this is not a valid VAT invoice.
The current POS interface may show English labels (Pay, Confirm, Settings, Returns, Recent sales…) — this guide includes the Vietnamese meanings so you can compare them.
Receiving stock and inventory counting for the store are done on the shared Warehouse screen — see the Warehouse & Inventory guide.
