Not paid IBI but nothing outstanding?

[fyfin]

Our friends are selling their apartment in the block where I am President and they asked me about IBI so I told them when it would have come out of their bank and how much approximately it would be. But, when they checked bank statements for last 3 years, there was nothing like that amount on there. As they don't live here there's actually very little going through the account so easy to check. Basura and agua were there, taken as direct debits.
So as they speak no Spanish I went to the town hall with the relevant information including both their Nie references as they weren't sure which one was used as it was a joint purchase 8 years ago.
The guy in the town hall was very helpful and printed out the invoice as he said the current year (previous year really I suppose) hadn't been paid. I asked if any previous years were also outstanding and he said No, only current. I had previously checked on the Diputacion website where you can check easily for outstanding bills in Almeria, and in case anyone is interested here is the link https://app.dipalme.org/portaldomi/port ... ionObj.zul . I have used this previously to make payments for vehicle tax etc for friends who don't have direct debits set up.
What was very strange is that when I checked against both his and her details (at that time we didn't know which was used) nothing was outstanding, yet the town hall guy was able to print an invoice with the overdue penalty of 10%.
They went to their bank to pay the invoice and when they asked about a direct debit the bank told them it had never been set up so it appears they have never paid IBI and according to the town hall and the computer system they don't owe anything except the one year now paid.
I double checked the details on the invoice now printed and the only difference is the address to which invoices would have been sent which is their previous address in another town. The only explanation I can come up with is that someone else is paying their invoices LOL
.