Method of accounting for professionals

There's no such rule that professinals shud follow cash system of accounting only. They can follow cash system or mercantile systme of acounting.  But considering the nature of business of professionals, there are no inventories, creditors, debotrs involved on a large volume unlike in trading & manufacturing busniess. So it will be prudent to follow cash system of accounting.

However in case of big firms, werhe the volume is large, numerous number of clients big & small, so in that cae it would be prudent to follow mercantile system of accounintg.