We cannot credit transactions until they have the proper number of confirmations on the block chain. Bittrex does not control the block chain nor can we make it go any faster. The transaction time is controlled solely by the block chain of the coin you are depositing. If your transaction is confirmed in the block chain and still has not been credited please let us know.
For Bitcoin you can enter your transaction id here to check if it is confirmed. Again if it is an unconfirmed deposit we cannot credit it or make it go faster: https://blockchain.info
To check if your deposit is confirmed on a different chain, please use a search engine and search for Coinname block explorer, which should lead you to a block explorer for that coin.
Does your coin require a tag/paymentid/memo/message?
Please make sure to check the deposit instructions for each coin. If you do not follow the instruction provided your coin may not be credited. If you realize that you did not include the proper tag/paymentid/memo/message please submit a ticket and provided support the full transaction hash of your deposit. If you do not provide the transaction hash we will be unable to credit your coins. The typical SLA for deposits without message is up to two weeks.
Did you send your coins to the address generated for that specific coin?
Bittrex has many coins. It is common for users to generate an address for one coin and then deposit a different coin to it. In some circumstances we may be able to retrieve these coins. If you sent your coin to a different coin's address you'll need to submit a ticket telling us the coin name, the address you sent the coin to, the transaction id (txid), and the amount of coins sent. This type of deposit mistake can take over 2 weeks to be credited.