If you are working mostly for private individuals, non VAT
registered buisnesses or buisnesses which primerally perform VAT exempt * activities then registering for VAT when you don't have to is most likely not in your financial interests.
If you are working mostly for VAT
registered buisnesses who perform primerally vat - liable (including zero - rated) activities then registering for VAT is likely in your financial interests (though it does mean more paperwork).
Not exact matches
If you are providing VAT - liable services (you probablly are) and you
register normally for VAT then you will be able to reclaim VAT on your
buisness purchases but you will have to charge VAT to your clients.