Harlow is one of a few towns outside London that operates Blackcabs.
Minicabs and Blackcabs are both licensed by Harlow Council, both are subject to almost the same licence fees.
There are many differences between them.
Blackcab taxis are Hackney carriages, the same as in London, these can be hailed anywhere, they operate from taxi stands located around the town, there is one at Harlow Station.
There are about 54 licensed blackcab taxis (most operate in the daytime.)
Blackcab taxis are the only Harlow taxis allowed by Essex County Council to use the bus lanes.

Minicab taxis are private hire taxis (because of the black cab status of Hackney carriage) these have to be booked in advance, they cannot be hailed,they are not allowed to have ranks.
Harlow minicab Taxis are not allowed to use the bus lanes as it would be against Essex County Council Policy .
Any minicab type taxis from outside Harlow are able to use the bus lane, this is because in their home towns they don't have black cab taxis and are licensed as Hackney carriages.
There are about 200 licensed minicab taxis in Harlow, without them night life in Harlow and the Police would have severe difficulties.

On the train
As a rule of thumb coming from the direction of London
I normally order a minicab just before the train reaches Broxbourne Station, I might have a little wait at Harlow station.
If you know what time your train should arrive at the station it's better to book in advance, they do get very busy at peak times.

One important difference to remember is price;
I used a minicab taxi to get from my home to Harlow station, price £3.20p
I used a Blackcab taxi for the return journey, the cab had nearly exceeded the mini cab price for the whole journey before we had passed Harlow Station roundabout!
It cost £5.60 for the return journey using a Blackcab.