Saturday Night When the POS Goes Offline
At SpeedCell, a mobile-accessory shop in Guwahati, the broadband line fails at 5:40 pm on a Saturday. The POS cannot reach the GST server, so the cashier opens a plain bill book. In the next 45 minutes the shop bills 22 customers. One customer pays ₹1,499 by UPI; her bank debits the account and shows success, but the offline POS records nothing. A second customer is charged ₹299 twice because the cashier swipes the card, sees no response, and swipes again. A third insists on a printed GST invoice; the cashier writes one by hand with no serial number. At closing, the cash drawer is ₹1,200 short of the manual-bill total. The owner wants to know what to tell the three customers tonight, how to close the day's accounts, and how to stop this becoming a tax or reputation problem. Accessories carry 18% GST.
1. What should the cashier and owner do tonight for each of the three customers?
Read the worked answer
UPI customer (₹1,499): Do not ask her to pay again and do not tell her the payment failed while her bank shows a debit. Record her UPI reference, take a screenshot or SMS copy, and issue a manual receipt marked 'payment under verification'. Verify against the bank/merchant app and statement the next morning. If the credit is not received within one working day, raise it with the payment service provider and give her a written acknowledgement.
Double-swiped card (₹299 twice): Check the card machine and bank settlement for the day. If both amounts are captured, refund the duplicate to the same card and give the customer a reference number; if only one is captured, explain with the settlement record. Log the incident either way.
GST invoice requested: Never hand over an unnumbered bill. For tonight, give a written acknowledgement with the item, amount and GSTIN, and issue a proper invoice from the regular series the next morning. If manual billing must continue, use a pre-authorised manual series with consecutive serials, HSN codes and 18% tax shown separately, and enter every manual bill into the sales register.
2. How would you close and reconcile the day's accounts, including the ₹1,200 cash shortage?
Read the worked answer
Reconcile in three parts: cash, digital settlements, and manual bills.
- Recount the drawer with two people present, checking the opening float, any cash advances or petty expenses, and whether a customer was given change from the wrong denomination.
- Add up the manual bill book page by page. Arithmetic errors, a missing bill leaf, or a bill not entered in the register are common causes of a shortfall. Total the UPI, card and cash amounts separately.
- Compare the total collected with the total billed plus opening float. The ₹1,200 difference should be written down as an unexplained shortage in the day's closing sheet, with the evidence attached. Never plug the gap with a false bill or by reducing recorded sales.
All manual bills remain part of turnover and must be reported in the GST return for the period, with output tax at 18%. Keep the offline POS log, manual bill book, bank statements and card settlement report together for the accountant and for any later audit or customer dispute.
3. What controls would you put in place so that a 45-minute outage does not create duplicate charges, unverified UPI payments, unnumbered invoices or cash shortages?
Read the worked answer
- Offline mode first: enable the POS offline billing function and local invoice numbering, and keep a pre-printed manual bill book with a controlled serial range and a named custodian.
- One swipe, then check: train staff to swipe or tap once and wait for the terminal or the bank SMS; no repeat swipe without checking the last transaction. Put the rule at the counter.
- UPI verification: verify with the merchant app or bank SMS, not with the customer's phone screen alone. Record the reference on the bill.
- Dual control at closing: two people count cash and sign the closing sheet; the day's manual bills are entered into the system the same evening.
- Segregation and CCTV: the person billing should not be the only person reconciling; keep the counter under camera coverage.
- Downtime drill: keep a hotspot or backup connection and a written one-page procedure, and test it once a quarter. Brief staff that an unnumbered bill is not a valid tax invoice.