A Swedish IBAN is always 24 characters long. Here is what each part of it means, with a real example broken down field by field — and a checker that runs on your machine.
Sweden keeps only three digits for the bank and gives the remaining seventeen to the account. Domestically, Swedes still use the clearingnummer and account number as a separate pair, and many also pay by Swish rather than by transfer.
The two digits straight after SE are not part of the account — they are a checksum over everything else. Move the first four characters to the end, turn every letter into a number (A=10 … Z=35), divide the result by 97, and a genuine IBAN always leaves a remainder of exactly 1. That is what the box above is doing, on your machine, with nothing sent anywhere.
If the number is on a scanned PDF you cannot select, retyping 24 characters is where mistakes get made. Snip2Field sits on your Windows desktop: press a hotkey, drag a box over the IBAN, and it reads the field, runs this exact checksum and copies it — ready to paste into your books or a transfer form. Fully offline.
See Snip2FieldExactly 24, always. That is SE, two check digits, and 20 characters of account detail. Anything longer or shorter is not a valid SE IBAN, whatever else is right about it.
It is the 3 characters directly after the check digits. In the example SE45 5000 0000 0583 9825 7466, that is 500.
You can tell whether it was written down correctly: the check digits catch a single wrong character or two swapped ones. You cannot tell whether the account exists — only the receiving bank knows that, which is what the recipient-name check does when a transfer is made.