Adding a telephone ringer

[#1]

I would like to add a telephone ringer. However I already have 4 telephones attached - giving a REN value of 4. The telephone ringer also has a REN value of 1 which if I connected it would give me REN value of 5. I've read that you shouldn't exceed a REN value of 4.
Is it possible for me to add a telephone ringer? Please would some kind person advise.

[#2]

Not an answer, but - unfortunately, phones are rated "upto" with integer values - so a true loading less than 1 is certified as 1 - see also the wikipedia entry.

[#3]

It's just a guideline - meaning basically that BT Openreach won't be interested if you complain of ringing problems and you have a total REN of 5.
Unless you have a particularly long line, chances are you'll be fine. Just try it and see - either it'll work or it won't - and no harm will be done in either case. 
4C (ex-BT)

[#4]

Thanks. If having a REN of 5 won't cause any harm I'll try it and if it works fine. Unfortunately I do have rather a long line from the cabinet to my property which caused some issues when I first had  ADSL and then fibre broadband installed.
Is there any device you can get which you can add to a phone line to increase the number of devices which can be attached?

[#5]

Yes
A DECT phone - one base station and several hand sets

[#6]

I would second Jims suggestion.
A DECT phone set with 2 or more handsets will still only take a REN of around 1. You can position the master base station near you phone socket and have the rest of the phones anywhere that is convenient.

[#7]

Thanks. I'll do that. It'll save problems with having ringers etc.

[#8]

You might want to look at the ones offered by BT with the call nuisance blocking system - you can use them to help stop cold callers / withheld numbers etc etc.
They cost a few quid more but well worth looking at for a long term investment.