The maximum number of orders/positions that you can have open at any given time is determined by two factors:
1. Your Verification tier.
2. Whether your order or position will fill as a maker or a taker.
Limits are across all pairs and are applied as follows:
|Tier 1-2||Tier 3||Tier 4|
|Open Positions (maker / taker)||50 / 70||120 / 150||220 / 250|
Example: You have 45 buy limit orders and 14 sell limit orders on XBT/EUR and ETH/EUR. The orders have not yet been filled, bringing the total to 59 open orders. You want to place a few more orders, but you are only verified to Tier 2. The maximum limit for open orders for Tier 2 accounts is 60. This means that you can only place one more order that stays open before you reach the maximum number of open orders.
Maker - An order which adds liquidity to the order book by not being matched/filled immediately with an existing order on the order book (i.e. the order has to wait to be filled).
Taker - An order which removes liquidity from the book by being immediately matched with an existing order on the order book (i.e. the order is filled immediately).