That is far more common in the US (basically paying expenses on your personal cards, expensing to the company after the fact). You can also advance on some expenses sometimes (this can be abused so there are some accounting restrictions on how you'd do it, etc.).

What is weird/scary (especially when not documented clearly and in advance) is moving your entire bank balance into a personal account. Aside from government/tax/legal, you'd have your investors (in a venture/angel backed company) to justify it to. It's justifiable in this truly exceptional case of SVB imploding and no other bank account being available. (It gets harder to justify in a larger company with lots of investors and more money involved; moving a $100mm balance in a company where you were down to 10% ownership to a personal account even in this situation would be weird AF and depending on the banks involved might cause you problems. I probably still would have emailed counsel and investors/etc. on thursday morning to ask what to do; likely would have sent it to lawyers to handle actually in the huge-account situation.)