What people ask when they are standing in it
Should I keep plunging it?
A plunger is worth a genuine try on a toilet or a sink, with a good seal and steady strokes rather than violent ones. If it has not moved in a few minutes of honest effort, more force is not going to fix it.
Stop if water is rising toward the rim or spilling. At that point you are adding pressure to a closed system and the risk of flooding the room outweighs the chance of clearing it.
It is the middle of the night and I can wait until morning, right?
Often yes, and that is your call to make with accurate information. A single blocked fixture with the water shut off to it is usually stable overnight if nobody uses it.
Waiting is a bad idea when wastewater is already on the floor or when more than one fixture is affected. It is also a bad idea when the only toilet in the house is out of service. After hours dispatch is priced higher across the trade, so the trade off is real either way.
Can you just come out and give me a price first?
A plumber does need to see which line is blocked and where the access is before quoting. Most companies charge a fee for that trip. That figure is confirmed with you on the phone before dispatch.
What we will not do is start work before you have heard a number and said yes to it. The decision point belongs to you, at the fixture, before anything is opened.
My landlord says I caused it, so am I paying?
That is between you and the lease, and we are not the right party to settle it. What we can do is describe factually what came out of the line and where the blockage was.
Ask for that description in plain language before the visit ends. A note saying roots were pulled from the main line reads very differently than one saying wipes were retrieved from a toilet trap.
Why does my tub back up when the toilet is the blocked one?
Because they share a line and the tub drain sits lower. When the shared branch or the main is obstructed, water takes the lowest opening it can find. In most homes that is a tub or a shower pan.
That symptom moves the job from a single fixture to the shared line. It is the clearest sign that the problem is further downstream than the toilet you are looking at.
Is a blocked drain an emergency or can it be an appointment?
It depends on containment rather than on the blockage itself. A clog with the water shut off, nothing spilling and another bathroom available is an appointment.
It becomes urgent when wastewater is leaving the fixture, when the house has one bathroom, or when the lowest drains are backing up. Those situations get worse with time rather than staying still.