Increasing voltage capability

Place resistors in series.

For example, 5x 200kohm 100V resistors is equivalent to 1 x 1Mohm 500V resistor.

Using multiple lower voltage resistors is often cheaper than a single high voltage resistor.

Also multiple resistors provides increased creepage distance against a single resistor of the same footprint (can be handy to avoid using a large TH resistor and stay with SMD resistors).