I dont believe that this is acceptable practice because the bonds are rated at the time they are issued, and both bonds and their issuers are periodically reevaluated to see if a ratings change is warranted. Bond ratings are important not only for their role in informing investors, but also because they affect the interest rate that companies and government agencies pay on their issued bonds.

Bond rating involves lot of cost for the raters and hence they need some type of benefit to
analyze the bond and to get the profits.

Credit agencies or Bond rating agencies should be impartial and have absolutely no links with the company.

Every credit analyst will offer a slightly different approach to evaluating a company’s credit worthiness; however, when comparing bonds on these types of scales, it’s a good rule to look at whether the bonds are either investment grade or non-investment grade.

The ratings of the bond over time also have major effects on the marketability of the bonds in secondary market, the ability for companies to borrow in other markets, the ability to issue stock, the analysts view the level of debt on the balance sheet and a major psychological aspect that how a company is viewed

so it very important activity for both point of view i.e for the investor and for the company so the practice of bond rating agency, To recoup those costs, some bond rating agencies have tied their ratings to the purchase of additional services. is not acceptable practice in my point of veiw