Replacing a Fiscal Storage Drive: Step-by-Step Without a Service Center

The POS started displaying "fiscal drive resource exhausted" — and there is no time to wait for a service center engineer when a line is waiting. On most modern POS terminals, you can replace the FN yourself in 15–20 minutes. The procedure is strict: skip a step, and you'll get error 235 or an unclosed archive that will take weeks to untangle.

1. When Exactly It's Time to Replace#

Two independent triggers — whichever is exhausted first will fire first:

The POS displays warnings for both situations in advance. You shouldn't wait until a complete lockout — a "last-day" replacement leaves no room for error.

2. If You Miss the Deadline — Lockout#

An expired or full fiscal drive prevents generating new receipts. This is equivalent to operating without a POS: if payments continue to be accepted without receipts during this time, each such transaction will have to be closed with a correction receipt after replacing the fiscal drive (see the article on POS breakdown in the corrections section). Replace the fiscal drive at the first warning, not after the lockout.

3. Step-by-Step Replacement Procedure#

Strictly in this order — changing the sequence of steps is the reason behind most frozen FNs.

1. Close the shift — print a Z-report; you cannot replace the FN while a shift is open.
2. Wait for all documents to be sent to the OFD — the unsent counter on the POS or in the OFD account must be zero. If it doesn't reset — fix the connection first (see the article on transmission diagnostics) before touching the FN.
3. Generate a "Report on FN Closure" in the POS service menu — it exports the archive and allows physical replacement.
4. Turn off the POS power — mandatory, as replacing under voltage can damage both the drive and the board.
5. Physically replace the FN: unscrew the compartment cover, remove the old drive, install the new one into the same connector, and close the case. For models sealed by a service center — opening without a service engineer may void the casing warranty.
6. Turn on the POS and generate a "Report on Registration Parameter Changes" — this is not a full re-registration, but a recording of the new FN number.
7. Submit the replacement in the FTS account — no later than the next business day. A delay is treated as operating with inaccurate registration data.
8. Link the new FN in the OFD account to the active contract.

4. Special cases: Error 235 and "receipts were not sent for 30 days"#

Error 235 "Storage resource exhausted" — when attempting to close the FN, the memory is already so full that some documents are not sent to the OFD. Urgently restore the connection (network, DNS, port) until the counter reaches zero; if the error persists, contact the FN manufacturer—the data sheet specifies a service helpline for emergency closure.

Receipts were not sent for 30 days — if the FN is already blocked for this reason, replacement does not eliminate the need to restore the connection: unsent documents must be transmitted or closed with a report before starting the procedure from Section 3 (full diagnostics can be found in the article on OFD transmission issues).

5. Cloud POS and Storing the Old FN#

Replacement in a cloud cash register is performed by the equipment owner — the cloud fiscalization provider — and not by you. Businesses usually only need to give advance notice as the expiration date approaches and pay for the new FN according to the plan; you do not need to read counters or generate reports yourself.

The old FN must be stored for five years from the date of decommissioning — the tax authority has the right to request the drive's archive during an audit at any time during this period, even if the POS has already been deregistered or sold. Sign a decommissioning report with the date and number, and store the FN together with the report separately, protected from moisture and static electricity.

6. After Replacement: "FN Does Not Belong to This POS" or "Incorrect Number"#

Both errors indicate a mismatch between the new FN data and the POS or the FNS/OFD portal. Check that: the FN serial number on the casing matches the one entered in the parameter change report; the report matches the FNS portal; the FN is genuinely new and was not previously fiscalized on another POS (a used fiscal drive cannot be installed); this exact number is linked in the OFD portal.

7. Example#

The cafe installed an FN-15 fiscal drive upon opening. After 13 months, the POS terminal started warning that the term was ending soon. The cashier closed the shift in the evening, and the manager checked the queue counter in the OFD account in the morning — zero, generated the FN closure report, turned off the POS, installed the new FN, generated the parameter update report, and entered the number into the FNS account on the same day. The POS was not idle for more than half an hour.

8. How to Do This in Cenaly#

Cenaly does not sell or replace fiscal drives (FN) — the operation is performed physically on the POS terminal or by its owner in the case of cloud fiscalization. However, Cenaly helps with the process:

• the POS → Receipts log stores a digital copy of every receipt — verify that all documents have been sent to the OFD before closing the FN;
• the Hardware section shows the status of the connected POS terminal via Cenaly Hardware Bridge — if the POS terminal disconnects during replacement, it will be visible immediately;
• transactions made without a receipt during downtime are processed using a correction receipt in the same section — see the guide to correction receipts.

9. Frequently Asked Questions#

Can we postpone the replacement for a couple of days while we find a new FN? No — an expired FN physically cannot generate a single receipt. Keep a spare FN on hand in advance, relying on early warnings about the upcoming expiration date.

Do we need to notify the OFD separately if the number has already been entered into the FNS account? Yes, these are two different accounts: the FNS records the replacement as a change in the cash register registration data, while the OFD treats it as a new source of documents for reception and storage.

An old receipt was never sent to the OFD before the replacement — is this a problem? Yes, if the counter of untransmitted documents was not cleared before the closure report. Check with the OFD and, if necessary, issue a correction receipt for the missing transactions.

Is it mandatory to call a service center (CTO) for physical replacement? No, if the casing is not sealed by a service center and the model supports self-replacement — this is usually explicitly stated in the cash register manual.

Related articles: cash register registration in FNS · FN for 15 or 36 months · receipts are not sending to OFD

This material is for informational purposes only and does not replace a consultation with an accountant, your OFD, or the FN manufacturer. Primary sources: Federal Law No. 54-FZ "On the Use of Cash Registers", guidelines from the FNS on the operation of KKT and FN (kkt-online.nalog.ru), manufacturers' fiscal drive manuals.