Do I need to use a micro filter?

[plugwash]

I've only once seen an ADSL router that came with one, but they came with practically every dialup modem sold in the UK.

 

[SUNRAY]

What supplier routers ?

A selection of Sky, BT, Virgin, Troolie. All on BT lines. I think (but wouldn't put any money on it) it's only the 2 most recent (Hub6 and Hub2) which didn't come with. In addition to the service providers 'free' routers, I used to install a fair number in commercial systems, typically about a couple a month, and I rarely used the 4P4C leads as there was no phone involved and therefore no point in adding any sort of adapter and hence a , TPLink probably being the more popular make.
However I should point out that I pretty much retired around 2016 so not up to speed with current situations

I've never seen one supplied. They are always RJ11 to RJ11. They discourage them as they can bypass using microfilters.
And when a phone is used on the line it will cause the BB to drop out

I'm not sure why that should happen and nothing I've ever encountered, the load presented to a phone line via a line filter is a higher impedance at the data frequencies than when connected direct, the only real effect should be (and the effect I have witnessed is) the data noise heard in the phone and an increase of data errors dependant on line length. Whether that gets as far as total dropout I have no experience of but with all the comments I've seen it would be silly of me to dispute.


When there is no copper phone line involved there is no requirement to connect a phone onto the line so totally no requirement to add an expensive unnecessary filter to add a potential fault liability (and yes they do go wrong, as do master sockets).

 

[opps]

Back in the day when I used to provide IT support to customers, I often came across faulty microfilters. The OP has no landline, and therefore doesn't need a microfilter.