In many companies the decision on changing ERP systems is taken in the autumn and the new system goes live on 1 January. Between those two dates the accounts department closes the year on the old system and, in the same weeks, prepares the data for the new one. The payment schedule often lives in an Excel sheet, fixed assets in a file kept by the accountant, and master data in an archive that has passed through two or three programs. Configuring the screens takes a few days, while preparing the data takes months: it is this second activity that sets the project calendar.
What moves from the old ERP to the new one?
Master data, the chart of accounts, open items and fixed assets with their opening balance move across; transaction history is imported only for the years that are needed.
Master data goes first. It is transferred through field mapping: for every item in the old system, its place in the new one is defined. When Aesir handles projects for changing ERP systems, the sequence is usually the same. First a trial import, then a check of balances and due dates, and finally the definitive import just before go-live, which picks up the entries made in the meantime. Corrections made to already transferred records between the trial and the final import have to be repeated, because the final import overwrites them. Freezing master data for a few days before the switch is therefore a sensible precaution.
A customer archive dating back to the late 1990s brings with it missing e-invoicing codes, VAT numbers that are no longer active and items that went out of production long ago. This import is the right moment to complete the data and to block obsolete items, or give them a validity date, without deleting them.
The chart of accounts determines how balances are opened
The choice that weighs most when changing ERP systems concerns the chart of accounts. Anyone who has built one over years of work tends to want to keep it. The request has a practical reason: with the same accounts in both systems, the closing balances of the old system become the opening balances of the new one without conversion.
The standard chart of the new ERP offers an advantage that shows over time. It is updated as regulations change and supports the software’s automated functions, including the reclassification of the financial statements under the Italian civil code format. For this reason the external accountant, when involved in the choice, often prefers it. With the standard chart the account codes change, and carrying the balances across requires a mapping table between old and new accounts.
In the projects Aesir runs, a middle way is often adopted. The company receives the standard chart, highlights the accounts it uses and asks for the changes it needs. Unnecessary accounts are hidden rather than deleted. The decision belongs at the start, together with transaction types and VAT codes, because the rest of the configuration rests on these three choices.
Then there is a calendar constraint. Balances in the old system become final only once the annual accounts are closed, several months after 1 January. The tidiest approach opens with provisional balances at go-live and records the final balances after approval. Meanwhile the old system stays active so that the year can be closed.
A painful first migration changes how the second one is planned
A family business of about twenty people, organised in three divisions, had already changed its ERP once. On that occasion it had kept its old chart of accounts and carried the balances across by hand, a job the head of accounts remembers as an ordeal. The master data went back about thirty years and had passed through several systems, so some customers still lacked an e-invoicing code.
When it came to changing ERP systems a second time, this time to Business Experience, the company faced two constraints. July to December were its busiest months, and the accounts team could give the project half a day a week. There was also a worry that the old system would be switched off on 31 December, before the year was closed.
The analysis showed that keeping the old chart of accounts would have cost a large share of the new ERP’s automated functions. Once consulted, the external accountant recommended the standard chart. The accounts team then highlighted the accounts in use and reviewed transaction types and VAT codes with Aesir. Master data import, with a clean-up of missing data, was scheduled for the summer, and configuration for September.
The old ERP had a perpetual licence and remains available for closing the year, so the fear of a switch-off disappeared. Go-live is set for 1 January with provisional balances, while the final ones will follow the approval of the accounts in spring. The work on balances moves from manual copying to a mapping table between the accounts, built during configuration.
Insight: when changing ERP systems, the last accounts on the old system close in spring, months after go-live. That is why the chart of accounts is chosen before go-live, with the accountant who will prepare those accounts.
How can a payment schedule kept in Excel be brought into the new system?
From go-live, due dates are generated by registered invoices; for earlier items, open entries are imported from Excel with the customer code of the new system.
In a metalworking subcontractor that machines parts to customer drawings, with two concurrent users on the ERP, the payment schedule had never been kept in the system. It sat in an Excel file and on printed sheets, and incoming payments were checked at the bank roughly once a week. The accounts team considered rebuilding it by hand ahead of changing ERP systems unrealistic. During the demo they named the main risk: a transcription error on a due date takes a second to make.
For earlier items, the Excel file can be kept until the open items run out. Alternatively, the invoices still open at 31 December can be registered, or the due dates alone can be imported. The import needs a fixed format, with due date, account and year of the item, and the customer or supplier code already assigned in the new system. Business Experience accepts pasting from Excel into any grid, provided the columns follow the expected order. An opening entry for the accounts has to be recorded in any case.
In the same demo the accounts team also saw the other half of the problem, knowing who has paid. The automated bank reconciliation tool downloads transactions through read-only access, never with payment authority, and matches them to invoices using keywords set for each bank.
Orders with VAT and VAT-exempt orders for the same customer
A second point concerned customers who had issued a declaration of intent, the Italian document that lets habitual exporters buy without VAT. Delivery notes with VAT and VAT-exempt ones for the same customer ended up on the same invoice. In Business Experience the tax condition is set on the order and passes to every related document. Summary invoicing then splits documents with different tax conditions, payment terms or banks into separate invoices, and a trial invoicing run lets the team check the result before issuing. The requirements are summarised on the Italian Revenue Agency’s page on the declaration of intent (in Italian).
In that negotiation the issue that carried most weight was integration with the CAD software that feeds production orders. The next step is a technical meeting with its vendor to define a staging database. This intermediate store exchanges data between the two programs without giving either of them direct access to the other.
Can fixed assets kept by the accountant in Excel be imported?
Yes: each asset gets its own record with description, category and opening balance at import, and the accountant validates the proposed rates.
The ERP derives the depreciation rate from the ministerial tables linked to the asset category and to the company’s classification. The preset rates are printed, and the accountant confirms or corrects them before the first calculation. For assets in their first year, depreciation can be set at 50% or 100%.
After go-live new assets enter from the purchase invoice: a dedicated transaction type opens the asset record when the invoice is registered. Depreciation can be run during the year or at year end, with provisional entries until confirmation, and the fixed asset register is printed by category. The accountant’s file stops being the only source, and the firm receives data that is already in order.
Changing ERP systems: the checks to close by November
How much work it takes for the company
For companies with two or three workstations, recent estimates for configuration and training range from eight to fourteen days, to be confirmed by the initial analysis. The internal workload is a separate measure. At the family business described above, the head of accounts set aside half a day a week from late June. The aim was configuration ready in September and go-live in January. Cleaning master data and extracting open items weigh mostly on internal staff, because only the people who use that data every day know what to keep.
Where the data sits before the switch
The table summarises where data usually sits before the switch and how it enters the new system.
| Data | Where it often sits today | How it enters the new ERP | Who checks it |
|---|---|---|---|
| Customer, supplier and item master data | Archive of the old ERP | Field mapping, trial import and final import | Accounts and purchasing |
| Chart of accounts | Old ERP | Standard chart with the accounts in use, or import from Excel | Head of accounts and external accountant |
| Open items | Excel file or printed sheets | Import of due dates with the new system’s codes | Accounts |
| Fixed assets | Accountant’s file | One record per asset with category and opening balance | External accountant |
| Opening balances | Old ERP, final once the accounts are closed | Provisional at go-live, final after approval | External accountant |
Before signing, or at the latest in the first weeks of the project for changing ERP systems, these checks should be closed:
- the go-live date and the cut-off date after which due dates are generated in the new system;
- the choice between the standard chart of accounts and the current one, made with the accountant before configuring transaction types;
- a trial import of master data, checking e-invoicing codes, VAT numbers and obsolete items;
- an extract of open items in a fixed format: due date, account, year of the item;
- a list of fixed assets with category and residual value, for the accountant to validate;
- the customers with a declaration of intent, to be set up on their orders;
- how long the old ERP stays available and who can access it;
- the weekly hours the accounts team can give the project during the closing months.
Who guides the changeover, and on what basis
Aesir Srl is a Gold Partner of NTS Informatica for Business Experience and follows projects from process analysis to configuration, from training to support after go-live. With other ERP systems and departmental software, such as CAD programs, available connectors are used or new ones are built. Aesir is also an MSP and MSSP under the same contract, with its own Tier IV data centres in the EU and replication between them. ISO 9001, 27001, 27017 and 27018 certifications sit alongside voluntary alignment with NIS2 requirements. We run projects across Italy and, on specific request, in Switzerland, the United Kingdom and the United States.
Frequently asked questions about changing ERP systems
Can the current chart of accounts be kept?
Yes, the chart of accounts can be imported from Excel after its coding has been assessed. It is worth comparing it with the standard chart together with the accountant, because the standard one is updated as regulations change and supports more automated functions.
When are balances opened in the new ERP?
Provisional balances are recorded at go-live, so day-to-day work starts on the first day. Final balances follow the closing of the accounts on the old system, which remains available for that reason.
Is all the master data from the old ERP imported?
It is imported through field mapping between the two systems, after a trial import. This is the right moment to block obsolete items and fill in missing data, such as customers’ e-invoicing codes.
Does information the old ERP did not handle find a place in the new one?
Yes, in the free fields of the item record, for example thickness or material. In Business Experience these fields follow the document from the order to the delivery note and the invoice, with a standard configuration that does not need rechecking at every upgrade, as the article on ERP customisations explains.
Do VAT-exempt orders from the same customer end up on separate invoices?
Yes, provided the order carries the correct tax condition. Related documents inherit it, and summary invoicing splits those with different conditions into separate invoices.
Let’s talk
In spring, with the accounts approved, final balances go into the new ERP and the project for changing ERP systems closes with the archiving of the old system. The decisions that make this possible are taken in the autumn, together with the accountant. If you would like to explore the subject or assess the situation in your own company, you can fill in the form at the bottom of this page or write to support@aesir-tech.it: we will arrange a free consultation and start from your numbers.