Blocked drains and backed up toilets - Advice

Hello, our house is an end terraced and our neighbour immediately next door says his downstairs toilet is backed up and might need access to our storm drain when someone comes out to have a look to see if there's a blockage, our downstairs toilet is fine but the drain where the kitchen sink empties into is also blocked. We can't get the draincover up ourselves to have a look as just had imprinted concrete done and is awkward to get up with our lack of tools. Surely our loo would be backed up too if the problem was in our drain, or would it?

Not necessarily if yours is the first in the loop . The blockage could be between yours and theirs therefore theirs backs up but yours carries on flowing ok . Happened in our yard . Someone was putting wipes etc down the toilet plus loads of fat down the drain .

Whether yours is below and they need to ensure they flush the blockage through it, or yours is above and it may have started to back up to yours, they may need access to make sure everything is cleared through. You know your drain is blocked which may be due to a blockage next door. If the solid matter has backed up it may need clearing even after next door’s is flowing again.