Since the last transfer of the number to another operator should be more than 60 days. The new number can be transferred immediately after activation.
Before, or immediately after, applying for a number transfer, visit the office of the “old” opsoz and check passport data. They must be a letter in a letter, as in a passport.
The minimum time to complete the transfer, it is the default period - 8 calendar days. In the application, you can specify a later date of transition, up to 6 months from the date of filing the application for number portability.
The transfer fee is 100 rubles. A part of the opsoks does the transfer for free, a part - compensates for the transfer fee by charging to the account / account.
In the office of the "new" opsoza, you will be given a new SIM card. Depending on the operator, the SIM card will be with or without a temporary number. The transferred number will be tied to the same account for which the temporary number was attached, so the balance will not be reset after transferring your number.
For a successful transfer, it is necessary not only to update the passport data, but also to maintain, until the transfer of the number, a positive balance with the "old" opsoss. The balance, after the transfer, can be transferred to the l / account issued for you or your bank account.
Before transferring the number, employees of the “old” opsoz can call and offer a discount or a non-public rate.
On the day of transfer, there may be interruptions in the provision of communication services.

Mts : not
Megaphone : not
Beeline : Yes
Tele2 : Yes

Mts : not
Megaphone : yes, ask for a "blank" without a temporary number
Beeline : no, but there was a case MNP - Discussion (Post by Morus # 86171874)
Tele2 : not

In 3G Yota, in most regions, the shape of media content, it defines it very simply: by Content-Type. You can get around any tunnel with encryption. That is, the main thing is that the Yota equipment in your packages does not see the Content-Type header!
For details and workarounds please contact the next topic.Bypass Internet distribution restrictions Yota

Excerpt fromRules for the provision of communication services of LLC "Skartel"

Official site
Online support service
How to make a sim card from a modem work in the smartphone
Withdrawals from the balance of YOTA without statements(relevance in question)