Navient services XXXX of my private loans and XXXX of my XXXX loans from when I attended the University of XXXX. Over the course of the last couple years, as I have repaid the loans, I have noticed multiple issues with how the allocate payments and how the interest is applied. In particular, I have decided over the last half year to make a plan to pay my loans off in the next two years, and so made amortization tables and created a plan to pay off my highest interest rate loans first. I noticed that when I had been mailing in extra cash in addition to my normal payments, there were glaring inconsistencies in how the money was being allocated across my various loans, and I was unable to determine a formula that would explain why the extra cash was being allocated as it was - other than a general pattern : the highest interest loans were receiving the least additional payment. This stands in contrast to what I have seen from XXXX XXXX, whose policy it is to at least give even allocation, regardless of interest ( obviously the most generous to the consumer is to allocate to the highest interest first, but I would not expect a company to do this by default ). In order to correct this issue with Navient, I had them ungroup my loans so that I could pay each individually, and signed up for auto-debit to take advantage of the interest rate deduction. However, I noticed XXXX additional issues at this time. When I pay an amount in addition to my debit amount, prior to the due date, Navient issues a warning that the auto debit will still occur in that month ( in addition to my off-cycle payment ). This was not the case - when I submitted the additional payment, it was for my highest interest rate loans only, and those loans did not also have an auto-debit transaction. The issue with this is that unless I had been on top of watching my statements, the company was not charging my account as they committed to do, and therefore I would end up paying more interest over time on my highest interest loans. The other issue I had noticed at this time was that the interest amounts on my amortization table did not match the interest amounts that were being deducted from my monthly payments. I know that Navient has settled ( a ) suit ( s ) in the fast for nefarious interest rate practices, and I suspect that they are still being dishonest with consumers in regards to how they calculate and charge interest on their loans. My amortization table is calculated for daily compounding interest, and is accurate for my XXXX XXXX loans. To summarize, I have loans serviced by XXXX different companies : XXXX XXXX and Navient. XXXX XXXX is transparent, their website works well and based on how they allocate my additional payments and how the portion of my payment that goes toward interest matches my amortization table, I believe they are generally acting in good faith servicing my loans. On the other hand, I can say with a high degree of confidence that Navient lacks transparency in how it manages its student loans and actively places barriers in the way to its customers being able to manage the loans in the way that is best for them. My strategy with them is to pay off their loans as fast as possible because I believe they are not trustworthy with my debt, and I worry that there are many more consumers who are falling victim to these practices but just lack the tools and knowledge to see that they are being ripped off. Added together, over the course of me paying off my loans at the rate I was, allowing them to allocate my additional payments, I would have only lost several hundreds of dollars. But when you consider the total portfolio of loans they hold, that is a lot of money taken from consumers in an unfair way.