Mid March is a bit early for U.K. where mid April is safer, but not sure what the weather is like where you are. If it’s a bit unpredictable, you could sow a couple of batches and if you lose the first one to bad weather when you plant out, you have another batch in reserve.
You may have issues with low light inside the house causing them to grow weak and spindly, so don’t want to keep them inside for too long unless you have some artificial lights.