What MS Kaybee said.
If you have procedures in place to validate and cross-validate your data before you send your annual data by March 31st, you should be OK. If you only "spot check" your data, you might be in for a nervous experience.
Even though I have check and cross check procedures, I still get nervous and I have been doing this 30 + years. If I don't get a little nervous, I will probably miss something.
Hope this helps.