If it was I could manufacture money out of thin air just by never decrementing my ledger.
What actually happens is that banks have accounts at other banks. If you transfer say $230 from your account at SVB to PG&E at First Signature then what really happens is SVB decrements 1k from you and increments 1k to themselves and tells First Signature to decrement 1k from SVB's account and increment 1k to PG&E's account. (Take a look at #4 on how a wire transfer works [1]).
So when you want to transfer large sums it causes a bit issue as SVB might not have an account that size at the given bank. So they'll need forewarning so they can do a bunch of other transfers so that they do.
There's a practically issue with SVB having accounts at literally every other bank so if SVB and First Signature have an account at a common bank that works as well with just an extra step of transfers.
If it was I could manufacture money out of thin air just by never decrementing my ledger.
What actually happens is that banks have accounts at other banks. If you transfer say $230 from your account at SVB to PG&E at First Signature then what really happens is SVB decrements 1k from you and increments 1k to themselves and tells First Signature to decrement 1k from SVB's account and increment 1k to PG&E's account. (Take a look at #4 on how a wire transfer works [1]).
So when you want to transfer large sums it causes a bit issue as SVB might not have an account that size at the given bank. So they'll need forewarning so they can do a bunch of other transfers so that they do.
There's a practically issue with SVB having accounts at literally every other bank so if SVB and First Signature have an account at a common bank that works as well with just an extra step of transfers.
https://www.bitsaboutmoney.com/archive/bank-transfers-as-a-p...
[1]: https://en.wikipedia.org/wiki/Wire_transfer#Process