Obligations in the legal sphere towards tax are in varying capacities; individuals and corporate entities (law firms). The duty of a legal practitioner to tax payments can initially be captured by his role as a Nigerian citizen, hence, Section 24(f) of the Constitution of the Federal Republic of Nigeria, 1999. Section 41(3) of the Personal Income Tax Act, 1993 confers a more specific duty on all legal practitioners to file the returns of their income and claims for reliefs and allowances relating to the preceding year within 90 days from the beginning of every year. He is to obtain and complete the required forms from the govt. designated banks and make payment in line with the minimum tax payable for his category.
With due recourse to Section 20 the PITA, 1993 and Chief FRA Williams v Regional Tax Board (1965), deductable expenses for legal practitioners include books, journals, subscriptions to professional associations and conference fees. Capital allowance refers to claims in replacement for depreciation. In law firms, capital expenditure will include furniture and fittings, motor vehicles, buildings and books. In another vein, Withholding Tax is like an advance tax where deductions have been made from your practicing fee.  
As an employer, law firms have an obligation, subject to Section 80 of the PITA, to deduct appropriate tax from the total emolument of employees and remit same to the relevant tax authority on or before the 10th day of the following month. The firm however has another obligation in respect of payments to any individual or unincorporated entity of rent, commission, management / professional fees, consultancy fees, technical service, directors’ fees, dividend, agency arrangements/agreements tenancy agreements and supplies.
The firm is to ensure that appropriate withholding tax must be deducted and remitted to the Lagos State Internal Revenue Service (LIRS). All clients are also to be encouraged to pay same, failure of which attracts a fine of 10% addition in line with Section 73 of PITA, 1993. Firms also have an advisory duty role to clients to submit for assessments, transactions on sale of assets that attract Capital gains tax and issues of stamp duties.
 From:  Esq Law Practice Magazine,  volume 2 issue 5, NBA Special Edition 2.