Transfer limits are listed per plan and apply to either NetIN or NetOUT, whichever reaches its monthly limit first.

Overages are billed at a rate of $0.10/GB over Transfer Limits for Basic or Standard VPS plans. Premium VPS plans come with Unlimited Transfer and do not have any applicable overage charges. 

Transfer Limit calculations are automatically reset to 0 GB on the 1st day of each month. If you would like to avoid Transfer Overage charges you can do so directly from your VPS dashboard by scaling your VPS plan to a larger plan size with a higher Transfer limit

Example: If you deploy a Basic Pico VPS with a limit of 500 GB Transfer, and produce 510 GB of total NetOUT transfer for that usage period, you could expect to see an additional $1.00 Transfer Overage Surcharge automatically applied to your next monthly invoice (10 GB over x $0.10/GB).