E-invoicing looks like a technical project and mostly isn't. The technical part — send a document, receive a response — is what the software solves. The part that actually consumes time is that your data now has to be accurate to a standard it never needed to meet before, because a third party will validate it automatically on every invoice.
The good news is that most of this work can be done today, before choosing any system — and it isn't wasted work, because it's work on your own data.
Start with item codes — always the longest step
Most tax systems require every item you sell to be mapped to an approved standard code. That's not a software step; it's a decision per line in your catalogue, and it needs someone who knows the goods rather than someone who knows the software.
The practical method: export your catalogue to a file, sort it by number of times sold descending, and code the best-sellers first. In most businesses the top twenty percent of items covers the large majority of invoices, so you become practically ready well before the catalogue is finished.
Then customer records
Systems validate customer details on submission, so an incomplete record surfaces as a rejection on the first invoice rather than before it. The trouble is that the gaps are usually invisible: your current software accepts a customer with no tax number because it never needed one.
- Tax registration numbers for business customers — verify them now, not at submission time.
- The full legal name as registered, not the name you know them by.
- The address at the level of detail the system requires — usually more than you keep today.
- A clear distinction between business and retail customers, because validation rules differ between them.
The administrative steps that have a waiting period
These don't depend on you but on other parties, so they should start early — otherwise they're what ends up holding you back:
Register the business
Each authority has its own registration portal, and the business details must match your commercial registration exactly. A minor difference in the name sends the application back.
Buy the signing credential
The electronic signature or seal is bought from an accredited issuer and has an expiry date. Know that date from day one and put it in a calendar.
Name an owner
One person who watches the status and knows what to do about a rejection. With nobody owning it, rejections quietly accumulate until the return is due.
What isn't worth worrying about
The document's technical format, the signing mechanism, the transmission protocol — all of that is the responsibility of whatever system you use, and you don't need to understand it to be compliant. Any vendor who makes the format your problem has handed you theirs.
Equally, don't replace a working system wholesale just for e-invoicing. The right question isn't "does my system support e-invoicing?" but "is my data ready, and who will connect it?" The first changes with a release; the second is your own work.