Changing POS Systems Without Closing for a Day

Close the old system's open work before you close the old system

Visa's Table 5-12 sets general approval response validity timeframes, measured from the date of a valid authorisation. Card-present transactions get 5 calendar days, as do merchant-initiated transactions, while cardholder-initiated card-absent transactions get 10 calendar days and 30 with an extended authorisation indicator. Table 5-14 sets the other half: where the final transaction amount is less than the sum of the authorised amounts, the difference must be reversed within 24 hours of transaction completion, and where a transaction is not completed at all, the reversal is due within 24 hours of the earlier of cancellation and the end of the approval response validity period. A cutover that leaves open pre-authorisations, unsettled tabs or an unclosed batch on the outgoing system is not a reporting inconvenience — it is a set of obligations with clocks already running. Batch out, settle, and confirm the deposits landed before the old terminals leave the counter.

The clearing tolerance is not the same on both platforms

Above the applicable floor limit, Visa requires the clearing amount and the authorisation amount to match unless a permitted variation applies. Table 7-10 lists them. Effective 21 February 2026 in the US Region, MCC 5811 (Caterers), 5812 (Eating Places and Restaurants) and 5814 (Fast Food Restaurants) are permitted a difference of up to 30%; in the AP, Canada, CEMEA, Europe and LAC regions the same MCCs are up to 20%. Taxicabs and limousines (MCC 4121), drinking places (5813), beauty and barber shops (7230) and health and beauty spas (7298) are up to 20%. Cruise lines and lodging are up to 15%, vehicle rental the greater of 15% or USD 75, and other cardholder-initiated transactions in a card-absent environment up to 15%. The amounts must always match following a partial authorisation response. If your new system handles tip adjustment, delayed charges or incremental amounts differently from the old one — or if your MCC changes during the move — that is the rule the difference is measured against. Our tip adjustment guide covers the restaurant case in detail.

A new device is a new set of acceptance requirements

Visa's Table 5-8 requires an acceptance device to act upon card preferences for cardholder verification or request online authorisation, accept all 16-digit payment credentials, and make available to the cardholder all transaction interfaces the merchant supports. Contact chip devices must be chip-reading devices approved by EMVCo, support contact chip-initiated transactions, and process the transaction using data read from the chip unless the chip is not EMV-compliant or the reader is inoperable. Devices in a face-to-face environment must activate the PIN pad to enable PIN transactions. Confirm the replacement hardware meets these before go-live rather than discovering a gap from a decline pattern. Visa also prohibits splitting a transaction across two or more transaction receipts, which is the workaround staff reach for when a new device misbehaves mid-shift.

Misconfiguration shows up as qualification, not as errors

A POS that is working is not necessarily a POS that is sending what the schedule expects. In Visa's US consumer credit tables effective 18 April 2026, Non-Qualified Consumer Credit is listed at 3.15% + $0.10, and the Electronic Interchange Reimbursement Fee program sits above the CPS programs it replaces when data is missing. A new system that keys transactions the old one dipped, omits data elements, or settles late does not produce an error message; it produces a statement one month later with a different mix on it. Pull the first full statement after cutover and compare the fee program mix against the month before, rather than only reconciling totals. Our downgrade guide covers how to read that comparison.

Stored credentials do not move with the catalogue

If the new platform holds cards on file, Table 5-22 applies from the first transaction. After a cardholder agreement has been completed in writing and before the first transaction occurs, the merchant must submit an authorisation request for the amount, or an account verification if no payment is required, and must not store the credential if that request is not approved. Transactions using a stored credential must use POS entry mode code 10 and, for recurring, installment or unscheduled credential-on-file transactions, the appropriate indicator. If a merchant-initiated stored credential transaction is declined, the merchant must notify the cardholder in writing and allow at least 7 calendar days to pay by other means. The vault itself is a separate project with its own PCI obligations, including the Council's condition that systems which previously held cardholder data be examined to confirm all traces were securely deleted. Our vault migration guide covers that end.

An illustrative sequencing example

Illustrative example, made-up round numbers. A single-site restaurant plans a Tuesday cutover. Monday close: run the final batch on the outgoing system, confirm every open tab is settled and every unused pre-authorisation is reversed, and export catalogue, tax rules, gift card balances, loyalty balances and 24 months of reports. Tuesday morning: bring the new system up, run 10 low-value live transactions across each interface — dip, tap, keyed, and a tip-adjusted sale — and verify each one settles and appears in the deposit. Keep the old hardware on the counter, powered but not taking new sales, until the outgoing provider's final deposit clears. Two weeks later, compare the first full statement's fee program mix against the previous month. The point of the sequence is that no clock from the old system is still running when the old system stops being watched.