I'm in a similar situation, too. I earn relatively low income but pay out €300 per month for tax and gestor.
I closed down for three months in the summer (too hot for hiking) and stopped paying the Social Security for that duration on advise from my gestor.
When I restarted it was simply a phone call to him and he started it all up again automatically. Very simple and easy. I suspect I will do the same again this coming summer.
The up-front payments are completely anti-small business. There is no other word for it.
I'm investigating opening my business back home in Dublin and employing myself through that company.
Here is a little info I gleaned from the internet.
the information is relevant to Irish citizens but its probebly the same for UK citizens too.
"Workers posted to another EU country
You have certain specific rights if you are a posted worker, that is, you work for a limited period of time in a member state other than the one where you normally work. If you are to be posted for a period of more than a month, your employer must inform you in writing, before you leave, of your pay and working conditions while you are abroad.
You will usually remain affiliated to the social security system of your country of origin. You may pay income tax in that country as well but the situation varies between member states. You can find out about health and social security entitlements for posted workers in 'Further information' below.."
You are a posted worker if your employer sends you to work in another country on a temporary basis. From 1 May 2010 the period of the posting is 24 months (was 12 months) or less. If you are posted to another EEA state or Switzerland you have certain rights as follows:
As a posted worker you generally will continue to pay your social security contributions in Ireland. You should apply for an A1 (formerly E101) certificate which states that you are insured for social security purposes in Ireland. This will exempt you and your employer from paying social insurance in the country to which you are posted. At least 4 weeks before you leave you or your employer should apply for the AI certificate. You can download the application form for an A1 (pdf) and it is also available from the PRSI Special Collection Unit of the Department of Social Protection (DSP). When you get the A1 certificate you will continue to pay your PRSI contributions in Ireland. There are further details about PRSI and posted workers on the DSP website..."