Why take the chance that your documents are anything less than perfect? It takes a second pair of eyes to identify errors in your documents; and rest assured - there are errors!!!
The first mistake will achieve a raised eyebrow, the second mistake will lower the reader's interest level, and the third mistake will almost certainly cost you that Grade 'A' pass, pay rise, or life-changing contract.
At GrammarProofing, your first error will be treated in exactly the same way as your last. Trained eyes will seek them out and correct them, finally making your document ready for its intended audience.