Water pressure measured but what does it tell me?

[Newproject2020]

We moved about a year and a half ago and after initially having an issue with the internal stop tap (it was very stiff and took a while to fully open up). Even now however we can’t run a second tap without a dramatic drop in pressure.
A friend suggested getting the pressure and flow checked at the external stop tap to make sure that there’s no issue between that and the house (our house does have some age).
So the water company measured at the stop tap on the road and then also measure the same at an external water tap.
The figures are:
Stop tap Pressure = 5.3 bar with flow of 25litres
Outside tap Pressure = 4.7 bar and flow starts at 14litres but drops to 6.

But...what now? Not sure whether that’s fairly normal. Is the pressure ok but an issue with flow? And if that is an issue what is the next step to get it sorted?

 

[CBW]

The pressure will remain similar, unless obvious restrictions, it’s the flow rate that’s being reduced. Again I’d be looking for a restriction, probably the incoming stopcock if this is what you have struggled with initially.

 

[Newproject2020]

The one inside the house? That, we know is now fully open. So what can affect flow rate? What do we need to check out and where should we start?

 

[oldbutnotdead]

Your internal stop tap may have dismantled itself a bit while you were struggling with it, thus obstructing the water flow, so first job is to replace it (good quality ball valve may be a better option). After that you're looking at the pipe run from external stop tap to internal- what is it made of, what diameter is it

 

[Elkato531]

What type of pipe do you have between the external stoptap and the house. Upgrading to 25mm MDPE is probably the answer.