The process is very simple and just takes a minute by following the link below to your Operator’s Registration site.  If your system was provided by your Operator it may be preregistered (see product box insert).
In the USA:
If your operator is T-Mobile, MetroPCS, TruPhone, or another T-Mobile network operator please register your booster at: www.t-mobile.com/support/coverage/register-a-signal-booster
If your operator is AT&T, Aio, or another AT&T network operator please register your booster at: www.attsignalbooster.com
If your operator is Verizon, or another Verizon network operator please register your booster at www.verizonwireless.com/solutions-and-services/accessories/register-signal-booster